In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[901, 'I', 1101, 'S', '2893', 'P', 'n', 'o', 5221, 2651], ['t', 9147, 'Q', 'S', 'S', '2893', 'P', 'n', 'f', 'S', 3435, 'c']