In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[9781, 'V', '615', 'Y', '9405', '7001', '9541', '2853', '8039', '8971', '1911', 'M', '5153', 'v', '5229', 'q', 'w', 'O', 7765, 5553], [7921, 'O', 'C', 'F', 'Z', '615', 'Y', '9405', '7001', '9541', '2853', '8039', '8971', '1911', 'M', '5153', 'v', '5229', 'r', 3817, 'I', 'H', 'X', 'N']