In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['t', 6607, 'W', '7555', 'b', '7315', 'O', 'M', 7363], ['F', 'a', 1869, 2401, '7555', 'b', '7315', 'O', 'P', 7209, 'P']