In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[893, 6621, 'y', 'f', '7019', 'R', '1651', 'F', '645', 'U', 'r', 'o', 2683, 'x', 'G', 'S'], ['X', 'q', 445, 'U', 'p', 'W', 5553, 'f', '7019', 'R', '1651', 'F', '645', 'U', 'F', 3931, 6111]