In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['A', 'u', 5665, '8617', '8033', '1739', '9837', 'f', 'D', '5639', 'l', 'k', 7931], [8847, 3509, 'a', 'X', 3031, '8617', '8033', '1739', '9837', 'f', 'D', '5639', 'l', 'n', 'z']