In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['x', 8899, 7143, 'f', '5473', 'H', '6695', 'n', 'Y', 'E', 'f', 863], [8885, 'K', 'X', 'S', 'Q', 'f', '5473', 'H', '6695', 'n', 'Y', 'E', 'M', 6447, 'm', 'p', 4465]