In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[1231, 's', 173, 5941, '3555', '6355', 'b', '6543', 'q', 887, 'j'], [8593, 'l', 'w', 4757, '3555', '6355', 'b', '6543', 'i', 'z', 'N', 6721]