In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[3339, 603, 'M', '1621', '6473', '1801', 'B', 'P', 'w', 5929, 'I', 'B'], ['L', 'a', 5731, 2945, '1621', '6473', '1801', 'B', 'P', 'g', 2833, 'a', 'S', 'W']