In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[6469, 6921, 'o', '535', 'M', '307', '4981', 'n', '1359', '309', 'S', 'Y', 9635, 2635, 6325, 'l', 'x'], [3509, 'A', 1167, 'O', 'K', 'U', 'M', 'u', 'o', '535', 'M', '307', '4981', 'n', '1359', '309', 'B', 'C', 5527, 'j']