In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[3437, 'q', 7823, 's', 'L', 'l', 'X', 'r', 1877, 'f', 'f', 's', '5101', '6715', '289', 'y', 'g', 'n', 'M', '2031', 'd', '7943', '7223', '5499', 'z', 'b', 4985, 7193, 425, 1299, 8915, 'P', 'a', 457], ['a', 5873, 'X', 'P', 'H', 6981, 'm', 407, 'F', '5101', '6715', '289', 'y', 'g', 'n', 'M', '2031', 'd', '7943', '7223', '5499', 'u', 7567]