In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['m', 7797, 'l', 'D', 8885, 'Y', 'r', 'b', '4685', 'P', '8311', 'f', 'U', '5853', 'P', 'z', 4563], ['O', 'd', 7421, 947, 6693, 'Y', 'b', '4685', 'P', '8311', 'f', 'U', '5853', 'P', 'D', 7431, 'K', 'A', 'Y']