In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['X', 'H', 'N', 'a', 1447, '769', 'U', 'H', 'A', 'q', 'k', 'k', '8103', '821', '765', 'K', 'f', '343', 'U', 'i', 'Y', 'm', 1433, 'K', 'j', 3803, 1471], ['h', 'G', 'K', 'x', 5511, 'x', 'x', '769', 'U', 'H', 'A', 'q', 'k', 'k', '8103', '821', '765', 'K', 'f', '343', 'U', 'o', 'G', 'y', 3731, 'K', 'b', 'U', 'o', 'q', 'A', 'R', 'R', 4353, 151]