In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[8621, 8691, 'U', 'd', 'W', 4427, 'g', '9913', 'X', '7823', 'Q', '7251', 'm', '5461', 'i', 'E', 8345, 'U', 'R', 'r'], ['G', 4131, '9913', 'X', '7823', 'Q', '7251', 'm', '5461', 'i', 'G', 2367, 'B', 'g', 'p', 'F', 1241, 'v']