In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[2509, 6333, 'c', 1625, 'm', 4213, 'H', 5953, 'X', '9093', '7649', '5117', 'Q', 'Q', 'o', '1321', 'a', '7847', 'k', 1831], [667, 2903, 'Y', '9093', '7649', '5117', 'Q', 'Q', 'o', '1321', 'a', '7847', 'x', 2139, 'v', 8911, 2689]