In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[4519, 4089, 'Z', 'l', '421', '8751', '6361', 'o', 'W', 8369, 4541, 'b'], ['X', 'S', '421', '8751', '6361', 'o', 'S', 's']