In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[3607, 'F', 9639, 3439, 5321, 'W', 1693, 'f', 'v', 'U', 'm', '9625', '3439', '5685', 'W', 'W', '2621', '7591', '9737', 'U', 'E', 'a', 'Z', 4633, 7663, 9481, 2779], [6837, 'g', 'V', 'M', 's', 'c', 'D', 'U', 'm', '9625', '3439', '5685', 'W', 'W', '2621', '7591', '9737', 'U', 'E', 'a', 'Q', 'X', 5983, 8375, 3123, 6609, 'C', 4489, 5307, 9345, 7981, 2443]