In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['k', 'D', 'l', 5447, 1913, '8923', 'i', 'K', 'y', 'X', 'k', 's', 'p', 2515, 5609], ['r', 6977, 6873, '8923', 'i', 'K', 'y', 'X', 'k', 'v', 'c']