In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['I', 9801, 'c', 'F', 'R', '71', '4969', 's', 'k', 6621, 3881], ['N', 2605, 7329, 'c', 'F', 'R', '71', '4969', 'w', 'F', 't', 8065, 9389]