In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['G', 'U', 'b', 'k', 'P', '631', 'N', '6759', 'a', 'w', 'D', '4255', '9829', 'K', 'I', 'D', 'm', 'x', 'r', 4283, 8259], [909, 'V', 'f', 'W', 'P', '631', 'N', '6759', 'a', 'w', 'D', '4255', '9829', 'K', 'i', 't', 1201, 6515, 'S']