In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['K', 'F', 's', 'W', 'P', 'Q', '1807', '6903', '6629', '5515', 'h', 'Q', 'X', 'u', 4709], [6987, 'x', 5283, 'D', 'P', 'Q', '1807', '6903', '6629', '5515', 'N', 'o', 'q', 'd']