In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['F', 1869, 'p', 't', '8525', '6807', 'S', '2429', '849', 'I', 'N', 'E'], [3945, 4773, 3553, 9839, '8525', '6807', 'S', '2429', '849', 'x', 4057]