In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[21, 8857, 9909, 9961, 9065, 'W', '3721', 'G', '4359', 'O', 'h', '849', 'G', '8333', 'Y', '4129', 'g', '4559', 'a', 'G', 'I', 'N', 'Q', '981', 'Y', 'B', 'f', 8271, 'v', 7243, 7471, 8421, 'x', 'P'], ['F', 4823, 'i', 9245, 'O', 809, 'T', 8287, 237, 'G', 3733, 'W', '3721', 'G', '4359', 'O', 'h', '849', 'G', '8333', 'Y', '4129', 'g', '4559', 'a', 'G', 'I', 'N', 'Q', '981', 'Y', 'B', 'e', 3233, 6083, 'x']