In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['e', 1365, 'k', 'Q', '9373', 'f', 'z', 'Y', 'j', 4447, 7511], ['C', 6641, 'C', '9373', 'f', 'z', 'Y', 'A', 'X']