In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[457, 'X', 'C', 'f', '3773', 'Q', '4135', 'O', 'n', 'F', 6069], [5345, 1723, 'M', 1773, 'f', '3773', 'Q', '4135', 'B', 'E', 'n']