In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[3917, 8517, 5843, 'T', 'V', 'b', 6923, '6061', 'W', 'W', 'b', 'M', '6505', '8597', 'e', 6717, 'l', 'P'], ['e', 'z', 'B', 'D', 'F', 'C', '6061', 'W', 'W', 'b', 'M', '6505', '8597', 'i', 'U', 'C', 9757]