In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['f', 'A', '289', 'r', 'e', '6975', '919', '1563', 'k', 'Q', 'm', 9251, 6313, 1003], ['W', 'k', '289', 'r', 'e', '6975', '919', '1563', 'k', 'Q', 'r', 'f']