In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['B', 'g', 7251, 6535, 'D', '4003', 'r', '5953', 'E', 'H', 8419, 7265, 8497], ['t', 2569, 8987, 2903, 'D', '4003', 'r', '5953', 'E', 'X', 'a', 'a', 'Z']