In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[4725, 'X', 4761, 2189, 'a', 'p', 'u', 'Z', 'X', 'z', 'S', 'r', 'C', '643', 'n', 'u', '6721', 'R', 'G', 'z', 8537, 7481, 3317, 8927, 2139, 2175], [559, 9871, 'X', 'I', 5003, 'B', 'Z', 'X', 'z', 'S', 'r', 'C', '643', 'n', 'u', '6721', 'R', 'G', 'c', 2683, 'Z', 'g', 6455, 'G']