In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[2489, 'C', 'v', 4351, 'Z', 'x', 'v', 3903, 's', 'E', '147', 'I', 'l', '3149', 'C', 'O', 'i', 'C', 'K', 'J', 'W', 't', 't', 4077, 'f', 3947, 'M', 9509, 'y', 'm', 8001, 1463], ['y', 4949, 4263, 2659, 'E', '147', 'I', 'l', '3149', 'C', 'O', 'i', 'C', 'K', 'J', 'W', 'h', 'Y', 'h', 1503, 'B']