In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[9635, 4025, 'i', 'c', '6597', 'j', '645', 'C', 'a', 'c', 8077, 9137, 4637], ['L', 'k', 'i', 'c', '6597', 'j', '645', 'C', 'a', 'x', 9437, 'F', 'i', 'M']