In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['s', 5121, 'f', 'w', 'e', '1875', '7907', 'Q', 'o', 'Q', 'S', 'I'], ['F', 'R', 'P', 'T', 'w', 'e', '1875', '7907', 'Q', 'o', 'Z', 'Q', 7981, 'G', 't', 'S']