In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[6695, 6281, 2867, 'v', 'U', '4969', 'u', 'D', 'q', 177, 3889, 'H'], ['C', 2121, 4185, 3481, 'E', 'v', 'U', '4969', 'u', 'D', 'd', 3657, 'u', 'X']