In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['n', 4819, 'U', 'E', '7535', '9271', '503', '6157', 'U', 'f', 2483, 'C', 'Q', 'K'], ['m', 'c', 9891, 9321, '7535', '9271', '503', '6157', 'U', 3321, 'Z', 'n']