In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[1099, 1917, 'r', 5699, 'X', 'Z', 'C', 2551, '1599', '2221', 'I', 'v', '5771', '4153', 'l', '5445', 'a', 5711, 'Z', 6739], ['r', 'G', 8791, 4847, 'V', 'U', '1599', '2221', 'I', 'v', '5771', '4153', 'l', '5445', 'C', 'W', 'C', 8753, 'Q', 9957, 'L']