In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[6851, 'y', 'T', 8671, 'T', 9413, 's', 'A', 'o', 'A', '8591', 'I', 'U', '9073', 'E', '9903', 'L', 'G', '4421', '7485', '7691', '4931', 'G', 'I', 2357, 'C', 'f', 141, 'C', 'o', 3099], ['C', 'M', 'D', 'x', 7619, 6395, '8591', 'I', 'U', '9073', 'E', '9903', 'L', 'G', '4421', '7485', '7691', '4931', 's', 'a', 't']