In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['i', 'Y', 'v', 'r', 'h', '5531', '9703', 'A', '4963', '7761', 'Y', 'F', 'F', 'i', 't', 'P', 2453], [1513, 5035, 'm', 'n', 'A', 'W', '5531', '9703', 'A', '4963', '7761', 'Y', 'F', 'F', 'i', 'A', 4421, 'C', 6701, 'i', 'z', 7561, 4397, 'I']