In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['i', 'L', 3011, 'k', 'm', '6297', '7531', 'b', 'W', 2587, 1277, 2315, 8553], ['A', 'I', 'r', 'Z', 4959, 'k', 'm', '6297', '7531', 'b', 'U', 'x', 's', 7149]