In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[9679, 'N', 2519, 35, 's', 'a', 't', '5381', 'S', '2309', '8061', '2363', 'v', 't', 'b'], ['r', 'K', 's', 's', 'a', 't', '5381', 'S', '2309', '8061', '2363', 'W', 'n', 'P', 8687, 6947, 'u']