In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[9085, 'B', 'D', 'Y', 'r', '6691', 'J', 2153, 'm'], [8907, 'f', 'h', 'x', 'D', 'Y', 'r', '6691', 'H', 'u', 2723]