In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['X', 'm', 3283, '9861', '2357', '8239', 'v', 's', 'a', 'D', 'x'], [1269, 'm', 2011, 'z', '9861', '2357', '8239', 'v', 'l', 261]