Messier Inc. has 34,000 common shares on January 1, 2012. On July 1, 8,000 shares were reacquired and retired. On August 31 and November 30, 9,000 and 6,000 shares were issued, respectively. Calculate
(a) The number of common shares issued at December 31, 2012,
(b) The weighted average number of common shares for 2012.