In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[4849, 3275, 'b', 1057, 'i', 7859, 'P', '1225', '1039', '2183', 'M', '5451', 'e', 'B', '4085', '3427', 'X', '1227', '6011', 'l', 4089, 6275, 2131, 'U', 4821], [6917, 3331, 7639, 'W', 9763, 3741, 'H', 2179, '1225', '1039', '2183', 'M', '5451', 'e', 'B', '4085', '3427', 'X', '1227', '6011', 'y', 6175, 1605, 1171, 'J', 'E']