In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['q', 'b', 'R', 'Q', 3585, 'r', 7455, '1689', '3921', '6149', '9615', 'Y', 'r', 'y', 'K', 'v', 1947, 223, 3135, 'u'], ['j', 871, 8135, '1689', '3921', '6149', '9615', 'Y', 'r', 'y', 'K', 'b', 7757]