In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['v', 'j', 'w', '7807', '9879', 'r', 's', '6061', 'r', 'e', 'i'], [5493, 6979, 'I', 'N', 6847, 'w', '7807', '9879', 'r', 's', '6061', 'z', 'U', 2721, 6657]