In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['z', 1119, 'u', '5977', '2387', 's', 'm', 'b', '7621', 'o', 2515, 'e', 'W', 'F'], [3987, 6205, 's', 'D', '5977', '2387', 's', 'm', 'b', '7621', 'O', 'Y', 'X', 'T', 'G', 'f']