First National Bankshares, Inc., a bank holding company, held substantially all of the voting stock of an equipment manufacturing corporation as collateral for a loan to the owner. On May 15 the borrower defaulted and on September 1, after proper notice was given, the bank foreclosed its security interest on the stock and exercised its rights to vote the stock at appropriate times. On December 31 the bank transferred the stock to a subsidiary corporation, FNB, Inc., to market the stock for sale more effectively. What is the longest time period that FNB, Inc., can possibly hold the stock?