In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[9901, 'J', 291, 8935, 4425, 'f', '7297', 's', 'L', '2335', '1257', 'G', 'Y', '3375', 'n', 'Z', 'k'], [4633, 4015, 'S', 'e', 'f', '7297', 's', 'L', '2335', '1257', 'G', 'Y', '3375', 'O', 'I', 7635, 'u', 7455, 'T']