IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY
Published on February 8, 2011
EXHIBIT 2
Waddell & Reed Investment Management Company - Tax ID No. 48-1106973
Investment Advisor registered under Section 203 of the Investment Advisors Act of 1940
Ivy Investment Management Company - Tax ID No. 03-0481447
Investment Advisor registered under Section 203 of the Investment Advisors Act of 1940