In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['Y', 9857, 4553, 'U', 641, 'I', 1651, 4375, 8999, 'g', 2485, 4989, 673, 'U', 1309, 'l', 'b', 'D', 3521, 'Y', 7777, 'j', '8919', 'g', 'X', 'k', 'B', 'V', 'x', 'O', '8183', '303', 'r', 'J', '5917', '1345', 'U', '7521', 'L', '2373', 'a', 'M', '2183', '6393', 'i', 'U', 'I', 'Z', 2703, 2839, 'y', 3877, 8983, 'Y', 'N'], [9251, 'i', 'e', 8773, 9147, 'u', '8919', 'g', 'X', 'k', 'B', 'V', 'x', 'O', '8183', '303', 'r', 'J', '5917', '1345', 'U', '7521', 'L', '2373', 'a', 'M', '2183', '6393', 7231, 8645, 3673, 2819, 2385, 9485, 7193, 'n', 'v', 'E', 'O', 'B', 9923]