In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['P', 'h', 9391, 'u', 9757, 'y', 'a', 'j', 'k', 'Y', '2091', 'U', 'p', 7959, 'F'], [1713, 2679, 'y', 'a', 'j', 'k', 'Y', '2091', 'U', 'V', 'r', 't', 'f', 8179]