In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[3945, 4295, 2985, 2057, 'Y', '5821', 'N', 'h', 'C', 'w', 'T', 'w', 'B', 't', '1259', '9833', 'l', 'e', 'O', '8141', 'e', 's', '99', '3257', 'Q', 'C', 'W', 'e', 7, 'k', 'b', 4449], [4649, 6553, 'M', 'C', 'S', 847, 'p', 'G', 'n', 'G', 'D', 'U', 'v', 'D', 3919, 'O', 4791, 'r', 'F', 6889, 4939, 'J', 'Y', '5821', 'N', 'h', 'C', 'w', 'T', 'w', 'B', 't', '1259', '9833', 'l', 'e', 'O', '8141', 'e', 's', '99', '3257', 'Q', 'C', 'B', 'x', 'y']