In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['Q', 'q', 1685, 'k', 'k', 'u', '3597', 'i', '7455', '6693', 'Q', '8991', '9539', 'Z', 'X', '9075', 'x', 3719, 2135], [1173, 139, '3597', 'i', '7455', '6693', 'Q', '8991', '9539', 'Z', 'X', '9075', 'z', 4727]