In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[6915, 2271, 'y', 'Y', 'b', 5057, 'P', 9261, 'E', 5709, 9345, 1191, 8399, 8371, 3641, 6653, 'W', 8721, 9471, 903, 2293, 'X', 'Y', '4217', 'l', '6047', 'X', '4883', '7515', 'l', 'B', '3735', 'P', 'x', 'C', '5019', 'g', '7135', 'n', '8715', '8457', '1029', 'Q', 'M', '7135', '1467', 'k', 's', 6639, 'G', 'm', 7745, 'b'], [8791, 2911, 8083, 3305, 'V', 'l', 'y', 'c', 9555, 9337, 2571, 6095, 'l', 'n', 'Y', '4217', 'l', '6047', 'X', '4883', '7515', 'l', 'B', '3735', 'P', 'x', 'C', '5019', 'g', '7135', 'n', '8715', '8457', '1029', 'Q', 'M', '7135', '1467', 'l', 'G', 1579, 't', 'N', 67, 'Q', 3953, 'H', 'S', 'i', 'O', 'w', 5459, 3295, 5121]