Item 3 of the Schedule 13D is hereby amended to read in its entirety as follows:

The total purchase price for the 4,673,981 shares of Common Stock beneficially owned by the Reporting Persons as of November 15, 2016, was approximately $27,658,109. The source of such funds was the assets of Discovery Equity Partners, including proceeds of margin loans under margin loan facilities maintained in the ordinary course of business by Discovery Equity Partners with a broker on customary terms and conditions. Discovery Equity Partners is the legal record owner of all of the Common Stock beneficially owned by Discovery Group and Messrs. Donoghue and Murphy.

Item 4 of the Schedule 13D is hereby amended to read in its entirety a follows:

The Reporting Persons acquired beneficial ownership of the securities reported herein for investment purposes.

On November 10 and November 14, 2016, the Reporting Persons engaged in discussions with members of the Company’s management regarding various matters relating to the Company, including its business, operations, management, corporate governance, executive compensation and strategic plans. The Reporting Persons discussed with the Company potential approaches to maximize shareholder value and the possibility of adding new independent directors and making changes to its charter documents to provide for the annual election of all directors by majority vote.  The Company, however, did not make any commitment to take any specific action.

The Reporting Persons intend to engage in further communications with members of the Company’s management and Board, and possibly with other shareholders and interested parties, with respect to the above matters and other matters the Reporting Persons deem relevant from time to time. Such matters are likely to include plans or proposals specified in clauses (a) through (j) of Item 4 of Schedule 13D, but the Reporting Persons may not pursue any such plan or proposal.

The Reporting Persons intend to review their investments in the Company on an ongoing basis. Depending on various factors, including, without limitation, the Company’s financial position and strategic direction, actions taken by the Board, price levels of shares of the Common Stock, other investment opportunities available to the Reporting Persons, concentration of positions in the portfolios managed by the Reporting Persons, tax considerations, market conditions and general economic and industry conditions, the Reporting Persons may take such actions with respect to their investments in the Company as they deem appropriate, including, without limitation, purchasing additional shares of Common Stock or other financial instruments related to the Company or selling some or all of their beneficial or economic holdings, engaging in hedging or similar transactions with respect to the securities relating to the Company and/or otherwise changing their intention with respect to any or all of the matters referred to in Item 4 of Schedule 13D.

Item 5 of the Schedule 13D is hereby amended to read in its entirety as follows:

The information concerning percentages of ownership set forth below is based on 51,215,910 shares Common Stock outstanding as of October 31, 2016, as reported in the Company’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2016.

Discovery Equity Partners beneficially owns 4,673,981 shares of Common Stock as of November 15, 2016, which represents 9.1% of the outstanding Common Stock.

Discovery Group beneficially owns 4,673,981 shares of Common Stock as of November 15, 2016, which represents 9.1% of the outstanding Common Stock.

Mr. Donoghue beneficially owns 4,673,981 shares of Common Stock as of November 15, 2016, which represents 9.1% of the outstanding Common Stock.

Mr. Murphy beneficially owns 4,673,981 shares of Common Stock as of November 15, 2016, which represents 9.1% of the outstanding Common Stock..

Discovery Group is the sole general partner of Discovery Equity Partners.  Messrs. Donoghue and Murphy are the sole managing members of Discovery Group.  As a consequence, Discovery Group and Messrs. Donoghue and Murphy may be deemed to share beneficial ownership of all of the shares of Common Stock owned by Discovery Equity Partners.

The transactions in the Common Stock effected by the Reporting Persons during the past 60 days are set out in Schedule A hereto.

No person other than Discovery Equity Partners is known to any Reporting Person to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, any of the shares of Common Stock reported herein.

DISCOVERY GROUP I, LLC,

for itself and as general partner of

DISCOVERY EQUITY PARTNERS, L.P.

Mark Buckley

Attorney-in-Fact for Daniel J. Donoghue

Attorney-in-Fact for Michael R. Murphy