In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[1545, 'x', 'c', '6647', '5353', 'C', '1323', '1679', 'e', 'a', 1271, 'V', 'x'], [8339, 'r', 4781, '6647', '5353', 'C', '1323', '1679', 'H', 9503]