In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[3471, 8357, 'O', 2889, 'g', '1747', 'S', '4449', 'p', '9721', 'n', 'f', 'x', 'S', 'P', '3481', '7313', 'm', '2343', '2401', '8705', 'w', 3449, 'Y', 'F'], ['l', 8067, 'A', 'G', 5495, 8875, 'L', 'y', '1747', 'S', '4449', 'p', '9721', 'n', 'f', 'x', 'S', 'P', '3481', '7313', 'm', '2343', '2401', '8705', 'x', 1671, 5623, 'h', 'M', 'K', 'U', 4751, 4367, 'i', 'k', 6973, 'A']