Task: Question Generation
Input (English): On November 2, 2014, the Cubs announced that Joe Maddon had signed a five-year contract to be the 54th manager in team history. On December 10, 2014, Maddon announced that the team had signed free agent Jon Lester to a 6-year, $155 million contract. Many other trades and acquisitions occurred during the off season. The opening day lineup for the Cubs contained five new players including rookie right fielder Jorge Soler. Rookies Kris Bryant and Addison Russell were in the starting lineup by mid-April, and rookie Kyle Schwarber was added in mid-June. The Cubs finished the 2015 season with a record of 97–65, third best in the majors. On October 7, in the 2015 National League Wild Card Game, Jake Arrieta pitched a complete game shutout and the Cubs defeated the Pittsburgh Pirates 4–0.
Output (English): Who did the team sign on December 10, 2014 as a free agent?