In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[2623, 3629, 3889, 'R', '1043', '2901', 'J', 'd', '1273', '7195', '6819', 'E', 'F', '6277', 'Q', 4245, 'n', 8117, 1715, 'H'], [1871, 5623, 8297, 'K', 7795, '1043', '2901', 'J', 'd', '1273', '7195', '6819', 'E', 'F', '6277', 'M', 'x', 'r', 'o', 4919, 5567]