In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['r', 'W', 'Y', 9709, 8217, 'y', 6815, 't', 343, 7875, 'E', 9109, '1001', '27', 'L', 'b', 'M', '1747', '2381', 'Y', '9143', '3069', 'u', '3813', 'O', '4883', '791', '857', '7369', '8893', 'D', '6233', '1811', 'U', 'I', 'C', 3725, 'F', 3745, 6635, 't'], [1989, 'W', '1001', '27', 'L', 'b', 'M', '1747', '2381', 'Y', '9143', '3069', 'u', '3813', 'O', '4883', '791', '857', '7369', '8893', 'D', '6233', '1811', 'U', 'Z', 7461]