Pls help me to answer this question:

• Xerxes tells you that he is a stockholder of ABC Corporation.Nine directors are to be voted in the election for the members of the board of directors.According to Xerxes, the total outstanding shares of the corporation amount to 20,000 shares.His group want to campaign for proxies to elect five out of nine directors.Advise Xerxes how many shares must he control to elect five directors.