In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['w', 2475, 'x', 'l', 'M', 'r', '667', '5645', 'L', 'C', 'J', 'D'], ['L', 7679, 6837, 8977, 'l', 'M', 'r', '667', '5645', 'D', 9271, 'E', 'U']