In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['R', 'F', 'D', 'K', '6421', 'd', 'C', '4415', '3965', '689', '3777', '4281', '2531', 'w', 'W', 'B', '5565', '4631', 'y', 'H', 'X', 2985, 'b', 6647, 5721, 'p'], [9837, 'X', 9495, 'K', '6421', 'd', 'C', '4415', '3965', '689', '3777', '4281', '2531', 'w', 'W', 'B', '5565', '4631', 'y', 'C', 'v', 'v', 8017, 'm', 'm', 2985]