In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[3139, 'A', 9221, 4931, '4627', '3185', '2939', 'u', '5975', '4583', 'K', 'C', 8955, 1919], ['P', 'e', 439, 6719, 'S', '4627', '3185', '2939', 'u', '5975', '4583', 'Y', 2377, 'H']