In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[1007, 'i', 't', 'L', 'v', 7931, 'L', 6439, 'Y', 6205, 1941, 'J', '571', 'p', '3131', '3711', 'Q', '1115', '8915', '239', 'H', '3863', '441', 'u', 'R', '5857', 'j', 'Q', 'u', 1785, 'B', 'K', 'M', 'm'], ['f', 4619, 'h', 'c', 'p', 6505, 'x', 689, 'n', 8393, 'F', 4931, 'A', 'S', 'a', 'J', '571', 'p', '3131', '3711', 'Q', '1115', '8915', '239', 'H', '3863', '441', 'u', 'R', '5857', 'o', 5973, 'j', 'p', 'W', 317, 4569, 7285, 8903, 's', 'm', 6847, 's', 335]