In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[6497, 9239, 'd', 2831, 'L', 'U', '1929', 'a', 'd', '4227', '1365', '1691', 'U', 'K', '4159', 'H', '4319', '3291', 'U', 4403, 'm', 'm'], [3579, 'i', 8299, 'I', 'N', 'j', 'Y', 'q', 6873, 9789, 'L', 'U', '1929', 'a', 'd', '4227', '1365', '1691', 'U', 'K', '4159', 'H', '4319', '3291', 'p', 'c', 571, 'Z', 9841, 'r', 5291, 'B', 3847, 8199, 4463, 'V', 6461]