In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['P', 's', 5011, '8399', 'P', 'R', 'i', '4607', '4003', 'r', '3395', '4373', 'B', 'j', 'R', 'u', 'E', 'c', 'e', 'M', 341], ['I', 'u', 7097, '8399', 'P', 'R', 'i', '4607', '4003', 'r', '3395', '4373', 'x', 'N']