In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['F', 5155, 799, 'O', 'u', 4123, 'n', 577, '7275', 'U', 'G', '17', 'h', '2741', '5273', '3275', '2921', '7929', 'Z', 'z', 443, 'P', 7499, 'm', 's', 'P', 6735], [7621, 'X', 5555, 3249, '7275', 'U', 'G', '17', 'h', '2741', '5273', '3275', '2921', '7929', 'Z', 'b', 345]