In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['k', 'U', 'm', 'A', '2865', '2813', '9419', '2819', 'W', '4499', '613', 'h', 'Z', 'h', 'L'], [7847, 4031, 3027, 'k', 't', 'X', 2105, 8687, 'A', '2865', '2813', '9419', '2819', 'W', '4499', '613', 'h', 'Z', 'F', 4139, 9539]