In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['u', 'U', 'X', '8457', 'Y', '9217', '815', '2443', '2961', 'x', 'c', '4961', 'P', 'Z', 'g', 'C', 's'], ['o', 659, 8425, 8699, 1221, 'Y', 3891, '8457', 'Y', '9217', '815', '2443', '2961', 'x', 'c', '4961', 'T', 9131, 7787, 5989, 2855, 's', 1529, 3609]