In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['Y', 8783, 'o', 'w', 'r', 'l', 'o', 't', '6131', '9519', 's', 2777, 'O', 'P', 909, 'd', 459], [9977, 7077, 5407, 'w', 'r', 'l', 'o', 't', '6131', '9519', 'n', 4507, 2253, 'S', 'n', 'v', 7455]