In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[21, 8515, 'f', 9593, 'A', '967', 'b', 'f', '9619', 'g', '4343', '2613', '6365', 'M', '7885', 'Y', '11', 'W', 'm', 'u', 'b', 'H'], [2295, 'v', 8345, '967', 'b', 'f', '9619', 'g', '4343', '2613', '6365', 'M', '7885', 'Y', '11', 'W', 'm', 'I', 8191]