In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['N', 3793, 'x', '4653', 'e', '9587', '2507', '9801', 'd', 'B', 507, 'm', 'p'], ['k', 6723, 7555, 'x', '4653', 'e', '9587', '2507', '9801', 't', 's']