In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[3905, 5041, 'D', 4891, 2991, 'J', 't', 'k', 7497, 'H', '3237', '8489', 'H', '9851', '5433', '7679', '3595', 'X', 'k', '3093', 'm', 'Z', 9115, 'u', 'B', 'M', 'P', 6261, 8787, 9407, 4847, 'I', 3787], ['u', 'm', 1231, 9321, 'H', '3237', '8489', 'H', '9851', '5433', '7679', '3595', 'X', 'k', '3093', 'm', 'V', 8765, 2265, 'J', 'U', 189]