In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['Y', 7617, 1121, '4399', '6467', '819', 's', '251', 'R', '8375', 'M', 'W', 'l', 'k'], ['M', 'C', 'K', 'M', 'q', 'Z', 4483, '4399', '6467', '819', 's', '251', 'R', '8375', 'M', 'P', 'j', 'w', 'q', 'Z', 'I']