In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[2301, 'q', 6757, 9621, 'x', '3269', 's', 'o', 'R', '475', '3623', '3793', 'p', 'H', 'J', 1243, 'e', 4959, 2471, 'w', 353, 'x', 'n', 'C'], [791, 649, 3259, 'J', 6001, 6679, 'i', 'x', '3269', 's', 'o', 'R', '475', '3623', '3793', 'p', 'H', 'f', 6547]