In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['M', 'l', 'C', '2049', 'J', 'O', '9309', 'f', 'x', 'X', '1823', '9351', 'W', '6579', 'K', 2087], [2439, 2777, 'w', 2015, '2049', 'J', 'O', '9309', 'f', 'x', 'X', '1823', '9351', 'W', '6579', 'W', 2455, 'X', 4455, 953, 9803, 5777, 'p', 'C', 9673]