In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[5971, 9729, 'n', 'h', 'M', 'W', 'u', 'B', 'I', '6041', 'P', '1301', 'Y', 'i', '9137', 'y', 'M', 1225, 1167, 'l'], ['r', 2487, 'e', 'j', 'r', 'R', 'K', 49, 5917, 3787, 'W', 'u', 'B', 'I', '6041', 'P', '1301', 'Y', 'i', '9137', 'y', 'H', 121, 2577, 'v', 'L']