SC 13G

VIKING GLOBAL PERFORMANCE LLC
VIKING GLOBAL INVESTORS LP
VIKING GLOBAL EQUITIES LP
VIKING GLOBAL EQUITIES II LP
VGE III PORTFOLIO LTD.
VIKING LONG FUND GP LLC
VIKING LONG FUND MASTER LTD.
O. ANDREAS HALVORSEN
DAVID C. OTT
THOMAS W. PURCELL, JR.

NASD


0000893949
Mednax, Inc.
65-0271219


Eric Komitee
203-863-5062

0001132625
vgp#55vgp

SC 13G

viking1.txt



                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                ________________

                                  Schedule 13G
                                 (Rule 13d-102)
                                ________________

INFORMATION TO BE INCLUDED IN STATEMENTS PURSUANT TO RULES 13d-1(b),(c)
              AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO 13d-2
                 UNDER THE SECURITIES EXCHANGE ACT OF 1934*



                                   Mednax, Inc.
                                 (Name of Issuer)

	               Common Stock, par value $.01 per share
                         (Title of Class of Securities)

                                     58502B106
                                  (CUSIP Number)

                                 May 14, 2010
          (Date of Event Which Requires Filing of this Statement)


     Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:
     [ ]    Rule 13d-1(b)
     [X]    Rule 13d-1(c)
     [ ]    Rule 13d-1(d)

___________

     *  The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which
would alter the disclosures provided in a prior cover page.


     The information required in the remainder of this cover page shall not
be deemed to be "filed" for the purpose of Section 18 of the Securities
Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that
section of the Act but shall be subject to all other provisions of the Act
(however, see the Notes).



Schedule 13G                                                 PAGE 2 of 16

CUSIP No. 58502B106
_____________________________________________________________________________
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               Viking Global Investors LP
_____________________________________________________________________________
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________
     (3)  SEC USE ONLY

_____________________________________________________________________________
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
               Delaware
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                  0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,390,987
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,390,987
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          2,390,987
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.1%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
               PN
_____________________________________________________________________________



Schedule 13G                                                  PAGE 3 of 16

CUSIP No. 58502B106
_____________________________________________________________________________
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               Viking Global Performance LLC
_____________________________________________________________________________
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________
     (3)  SEC USE ONLY

_____________________________________________________________________________
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
               Delaware
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,245,687
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,245,687
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          2,245,687
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          4.8%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
               CO
_____________________________________________________________________________




Schedule 13G	                                               PAGE 4 of 16

CUSIP No. 58502B106
_____________________________________________________________________________
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               Viking Global Equities LP
_____________________________________________________________________________
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________
     (3)  SEC USE ONLY

_____________________________________________________________________________
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
               Delaware
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    755,500
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    755,500
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          755,500
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          1.6%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
               PN
_____________________________________________________________________________




Schedule 13G                                                 PAGE 5 of 16

CUSIP No. 58502B106
_____________________________________________________________________________
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               Viking Global Equities II LP
_____________________________________________________________________________
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________
     (3)  SEC USE ONLY

_____________________________________________________________________________
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
               Delaware
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    42,500
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    42,500
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          42,500
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          .1%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
               PN
_____________________________________________________________________________




Schedule 13G                                                 PAGE 6 of 16

CUSIP No. 58502B106
_____________________________________________________________________________
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               VGE III Portfolio Ltd.
_____________________________________________________________________________
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________
     (3)  SEC USE ONLY

_____________________________________________________________________________
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
               Cayman Islands
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    1,447,687
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    1,447,687
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          1,447,687
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          3.1%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
               CO
_____________________________________________________________________________




Schedule 13G                                                  PAGE 7 of 16

CUSIP No. 58502B106
_____________________________________________________________________________
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               Viking Long Fund GP LLC
_____________________________________________________________________________
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________
     (3)  SEC USE ONLY

_____________________________________________________________________________
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
               Delaware
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                  0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    145,300
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    145,300
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          145,300
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          .3%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
              CO
_____________________________________________________________________________




Schedule 13G                                                  PAGE 8 of 16

CUSIP No. 58502B106
_____________________________________________________________________________
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
              Viking Long Fund Master Ltd.
_____________________________________________________________________________
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________
     (3)  SEC USE ONLY

_____________________________________________________________________________
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
               Cayman Islands
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    145,300
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    145,300
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          145,300
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          .3%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
               CO
_____________________________________________________________________________


Schedule 13G                                                  PAGE 9 of 16

CUSIP No. 58502B106
_____________________________________________________________________________
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               O. Andreas Halvorsen
_____________________________________________________________________________
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________
     (3)  SEC USE ONLY

_____________________________________________________________________________
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Norway
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,390,987
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                     2,390,987
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          2,390,987
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.1%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
               IN
_____________________________________________________________________________





Schedule 13G                                                  PAGE 10 of 16

CUSIP No. 58502B106
_____________________________________________________________________________

     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               David C. Ott
_____________________________________________________________________________

     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________

     (3)  SEC USE ONLY
_____________________________________________________________________________

     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          United States
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                     2,390,987
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,390,987
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          2,390,987
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.1%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
               IN
_____________________________________________________________________________





Schedule 13G                                                 PAGE 11 of 16

CUSIP No. 58502B106
_____________________________________________________________________________
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               Thomas W. Purcell, Jr.
_____________________________________________________________________________

     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [ ]
                                                                    (b)  [x]
_____________________________________________________________________________

     (3)  SEC USE ONLY
_____________________________________________________________________________

     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          United States
_____________________________________________________________________________

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,390,987
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,390,987
_____________________________________________________________________________
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          2,390,987
_____________________________________________________________________________
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
_____________________________________________________________________________
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
             5.1%
_____________________________________________________________________________
    (12)  TYPE OF REPORTING PERSON
               IN
_____________________________________________________________________________





Schedule 13G                                                 PAGE 12 of 16

ITEM 1(a).  NAME OF ISSUER:
             Mednax, Inc.

ITEM 1(b).  ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:
 1301 Concord Terrace, Sunrise, Florida, 33323

ITEM 2(a). NAME OF PERSON FILING:
	  Viking Global Performance LLC ("VGP"),
	  Viking Global Investors LP ("VGI"),
	  Viking Global Equities LP ("VGE"),
	  Viking Global Equities II LP ("VGEII"),
	  VGE III Portfolio Ltd ("VGEIII")
          Viking Long Fund GP LLC ("VLFGP")
	  Viking Long Fund Master Ltd. ("VLFM")
	  O. Andreas Halvorsen, David C. Ott and
	  Thomas W. Purcell, Jr.

ITEM 2(b).  ADDRESS OF PRINCIPAL OFFICE OR, IF NONE, RESIDENCE:
               The business address of each of the Reporting Persons is
               55 Railroad Avenue, Greenwich, CT 06830.

ITEM 2(c).  CITIZENSHIP:
VGE, VGEII and VGI are Delaware limited partnerships,VGEIII and VLFM
are Cayman Island Corporations, and VGP and VLFGP are both Delaware
limited liability companies. O. Andreas Halvorsen is a citizen of Norway.
David C. Ott and Thomas W. Purcell, Jr. are citizens of the United States.

ITEM 2(d).  TITLE OF CLASS OF SECURITIES:
            Common Stock, par value $.01 per share (the "Common Stock")

ITEM 2(e).  CUSIP NUMBER:  58502B106

ITEM 3.  IF THIS STATEMENT IS FILED PURSUANT TO 13d-1(b) OR 13d-2(b) OR (c),
CHECK WHETHER THE PERSON FILING IS A:

          (a) [ ]   Broker or dealer registered under Section 15 of the
                    Act

          (b) [ ]   Bank as defined in Section 3(a)(6) of the Act

          (c) [ ]   Insurance Company as defined in Section 3(a)(19) of
                    the Act

          (d) [ ]   Investment Company registered under Section 8 of the
                    Investment Company Act of 1940

          (e) [ ]   Investment Adviser registered under Section 203 of the
                    Investment Advisers Act of 1940: see Rule 13d-
                    1(b)(1)(ii)(E)

          (f) [ ]   Employee Benefit Plan, Pension Fund which is subject
                    to the provisions of the Employee Retirement Income
                    Security Act of 1974 or Endowment Fund; see Rule 13d-
                    1(b)(1)(ii)(F)


Schedule 13G                                               PAGE 13 of 16

          (g) [ ]   Parent Holding Company, in accordance with Rule 13d-
                    1(b)(ii)(G);

          (h) [ ]   Savings Associations as defined in Section 3(b) of the
                    Federal Deposit Insurance Act;

          (i) [ ]   Church Plan that is excluded from the definition of an
                    investment company under Section 3(c)(14) of the
                    Investment Company Act of 1940;

          (j) [ ]  A non-U.S. institution in accordance with
		   Rule 240.13d-1(b)(1)(ii)(J)

	  (K) [ ]  Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
                   If filing as a non-U.S. institution in accordance with
                   Rule 240.13d-1(b)(1)(ii)(J), please specify
		   the type of institution:

ITEM 4.   OWNERSHIP.

     A.  VGI
          (a)  Amount beneficially owned 2,390,987
          (b)  Percent of class: 5.1%
               (The Company's Quarterly Report for the quarterly period ended
	       March 31, 2010 filed on Form 10-Q on May 6, 2010 states
	       that as of May 3, 2010 there were 47,103,490 shares of Common
	       Stock outstanding.)

          (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         2,390,987
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 2,390,987

        VGI provides managerial services to VGE, VGEII,VGEIII and VLFM.
	VGI has the authority to dispose of and vote the shares of Common Stock.

	Based on Rule 13d-3 of the Securities Exchange Act of 1934, as amended
	(the "Act"), VGI may be deemed to beneficially own the shares of Common
	Stock directly held by VGE, VGEII, VGEIII and VLFM. VGI does not directly
	own any shares of Common Stock.



Schedule 13G                                               PAGE 14 of 16


     B.  VGP
          (a)  Amount beneficially owned: 2,245,687
          (b)  Percent of class: 4.8%
          (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         2,245,687
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 2,245,687

		  VGP, as the general partner of VGE and VGEII, has the
		  authority to dispose of and vote the shares of Common Stock,
		  par value $.01 per share directly owned by VGE and VGEII.
		  VGP serves as investment manager to VGEIII and has the
		  authority to dispose of and vote the shares of Common Stock
		  directly owned by VGEIII.  VGP does not directly own any shares
		  of Common Stock.

	Based on Rule 13d-3 of the Act, VGP may be deemed to beneficially
	own the shares of Common Stock directly held by VGE, VGEII and VGEIII.

     C.  VLFGP
          (a)  Amount beneficially owned: 145,300
          (b)  Percent of class: .3%
          (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         145,300
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 145,300

                  VLFGP , serves as the investment manager of VLFM and has the
		  authority to dispose of and vote the shares of Common Stock
	          directly owned by VLFM.  VLFGP does not directly own
		  any shares of Common Stock.

        Based on Rule 13d-3 of the Act, VLFGP may be deemed to beneficially
	own the shares of Common Stock directly held by VLFM.

     D.  VGE
          (a)  Amount beneficially owned: 755,500
          (b)  Percent of class: 1.6%
          (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         755,500
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 755,500

                   VGE has the authority to dispose of and vote the shares
		   of Common Stock directly owned by it, which power may be
		   exercised by its general partner, VGP, and by VGI, an
		   affiliate of VGP, that provides managerial services to VGE.

   E.  VGE II
          (a)  Amount beneficially owned: 42,500
          (b)  Percent of class: .1%
          (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                          42,500
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 42,500

                   VGEII has the authority to dispose of and vote the shares
		   of Common Stock directly owned by it, which power may be
		   exercised by its general partner, VGP and by VGI, an
		   affiliate of VGP, which provides managerial services to VGEII.

   F.  VGEIII
          (a)  Amount beneficially owned: 1,447,687
          (b)  Percent of class: 3.1%
          (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                          1,447,687
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 1,447,687

                   VGEIII has the authority to dispose of and vote the shares
		   of Common Stock directly owned by it, which power may be
		   exercised by its investment manager, VGP and by VGI, an
		   affiliate of VGP, which provides managerial services to VGEIII.
		   Viking Global Equities III Ltd. (a Cayman Islands Company) invests
		   substantially all of its assets through VGEIII.

   G.  VLFM
          (a)  Amount beneficially owned: 145,300
          (b)  Percent of class: .3%
          (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                          145,300
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 145,300

                   VLFM has the authority to dispose of and vote the
		   shares of Common Stock directly owned by it, which power may
		   be exercised by its investment manager, VLFGP and by VGI,
		   an affiliate of VLFGP, which provides managerial services
                   to VLFM. Viking Long Fund LP (a Delaware limited partnerhsip)
		   and Viking Long Fund III Ltd. (a Cayman Islands Company),
		   through its investment in Viking Long Fund Intermediate LP
		   (a Cayman Islands Company), invest substantially all of their
		   assets through VLFM.



Schedule 13G                                                PAGE 15 of 16

   H.  O. Andreas Halvorsen, David C. Ott and Thomas W. Purcell, Jr.
        (a)  Amount beneficially owned: 2,390,987
        (b)  Percent of class: 5.1%
        (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         2,390,987
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 2,390,987

	Messrs. Halvorsen, Ott, and Purcell, as
	Executive Committee Members of VGI, VGP, and VLFGP, have shared
	authority to dispose of and vote the shares of Common Stock
	beneficially owned by VGI, VGP and VLFGP.  None of Messrs. Halvorsen,
	Ott and Purcell directly owns any shares of Common Stock.

	Based on Rule 13d-3 of the Act, each may be deemed to beneficially
	own the shares of Common Stock directly held by VGE, VGE II, VGEIII and VLFM.

ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.
      If this statement is being filed to report the fact that as of the
date hereof the Reporting Persons has ceased to be the beneficial owner
of more than five percent of the class of securities,
check the following.[]

ITEM 6.   OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.
           Not applicable.

ITEM 7.   IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
                  THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY.
	Not applicable.

ITEM 8.   IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.
	Not applicable.

ITEM 9.   NOTICE OF DISSOLUTION OF GROUP.
	Not applicable.

ITEM 10.  CERTIFICATION.  (if filing pursuant to Rule 13d-1(c))
     By signing below each Reporting Person certifies that, to the best
of its knowledge and belief, the securities referred to above were not
acquired and are not held for the purpose of or with the effect of changing
or influencing the control of the issuer of the securities and were not
acquired and not held in connection with or as a participant in any
transaction having that purpose or effect.




Schedule 13G                                             PAGE 16 of 16

SIGNATURES

      After reasonable inquiry and to the best of our knowledge and belief,
the undersigned certify that the information set forth in this statement is
true, complete and correct.

DATED: May 24, 2010
			/s/ O. ANDREAS HALVORSEN
                        By: O. Andreas Halvorsen - individually and
                        as an Executive Committee Member of
                        VIKING GLOBAL PERFORMANCE LLC, on behalf
                        of itself and VIKING GLOBAL EQUITIES LP,
                        VIKING GLOBAL EQUITIES II LP,VGE III PORTFOLIO LTD.
                        and as an Executive Committee Member of
                        Viking Global Partners LLC, on behalf of
                        VIKING GLOBAL INVESTORS LP, and as
			an Executive Committee Member of
			VIKING LONG FUND GP LLC on behalf of itself
                        and VIKING LONG FUND MASTER LTD.

                        /s/ DAVID C. OTT
                        By: David C. Ott- individually and
                        as an Executive Committee Member of
                        VIKING GLOBAL PERFORMANCE LLC, on behalf
                        of itself and VIKING GLOBAL EQUITIES LP,
                        VIKING GLOBAL EQUITIES II LP,VGE III PORTFOLIO LTD.
                        and as an Executive Committee Member of
                        Viking Global Partners LLC, on behalf of
                        VIKING GLOBAL INVESTORS LP, and as
			an Executive Committee Member of
			VIKING LONG FUND GP LLC on behalf of itself
                        and VIKING LONG FUND MASTER LTD.


                        /s/ THOMAS W. PURCELL, JR.
                        By: Thomas W. Purcell, Jr.- individually and
                        as an Executive Committee Member of
                        VIKING GLOBAL PERFORMANCE LLC, on behalf
                        of itself and VIKING GLOBAL EQUITIES LP,
                        VIKING GLOBAL EQUITIES II LP,VGE III PORTFOLIO LTD.
                        and as an Executive Committee Member of
                        Viking Global Partners LLC, on behalf of
                        VIKING GLOBAL INVESTORS LP, and as
			an Executive Committee Member of
			VIKING LONG FUND GP LLC on behalf of itself
                        and VIKING LONG FUND MASTER LTD.


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