In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['l', 7671, 'W', 1363, 'v', 'O', 'P', '6883', '173', 'w', 'w', 'f', 'Q', 'k', 'Y', 6129], [8081, 'I', 'g', 'E', 'P', '6883', '173', 'w', 'w', 'f', 'x', 'W', 43, 3839, 'Y', 'd']