In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[6471, 'x', 'r', 6593, 't', 'J', '7543', '5551', '8005', '7451', 'H', '5161', '4529', '2969', 'g', 'I', 'R', 'm', '1003', '8403', '9321', '5355', 'Z', 'J', '8421', 'F', 'W', '6107', 'd', '3955', 'D', '5829', 't', 'n', 'e', 'r', 'L', 4961], ['W', 2121, 'p', 3629, 3201, 'd', 6889, 'O', 6505, 8519, 'd', 9989, 'F', 'g', 'z', 'c', 3523, 'S', 9921, 5125, 'w', 7413, 6691, 5443, 1415, 3143, 'C', 't', 'J', '7543', '5551', '8005', '7451', 'H', '5161', '4529', '2969', 'g', 'I', 'R', 'm', '1003', '8403', '9321', '5355', 'Z', 'J', '8421', 'F', 'W', '6107', 'd', '3955', 'D', '5829', 'k', 'Y']