In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[7971, 'z', 'F', 'h', 3797, 'l', '4923', '1603', 'd', '9677', 'G', 'R', '2389', '1989', '4695', 'C', 9671, 'L'], ['x', 6411, 2605, 'X', 'P', 4831, 'F', 'b', 5457, 4687, 'l', '4923', '1603', 'd', '9677', 'G', 'R', '2389', '1989', '4695', 'n', 3053, 4935, 2857, 'J', 1171, 3269, 'i']