In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['w', 7977, 7217, 3587, 'd', 'f', 'U', '2395', '6719', '1581', 'N', 'v', 6557, 'u'], [1413, 'r', 775, 813, 7451, 'f', 'U', '2395', '6719', '1581', 'N', 'b', 'f', 5387, 'W', 3891]