In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[6217, 'k', 4659, 'e', 'q', 2767, 775, 'L', 'v', 6525, 'y', 4027, 's', 'P', 2833, 'R', 'Y', '2123', 'C', '4301', '8351', '3091', '4973', 'D', 'I', 'Q', 'x', 'A', '1791', '467', 'q', '9865', 'X', 'Y'], ['Z', 'l', 1023, 'Y', '2123', 'C', '4301', '8351', '3091', '4973', 'D', 'I', 'Q', 'x', 'A', '1791', '467', 'q', '9865', 'x', 4183]