In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
[2831, 'M', 1409, 4059, 1783, 'Y', 4053, 'a', 'N', '7511', '5147', 'o', 'z', '1281', 'V', '1257', 'R', 'U', '2093', 'x', '6877', 'c', '9219', 'Z', 'w', 'f', 3901, 'm', 1731, 3133], [1869, 'y', '7511', '5147', 'o', 'z', '1281', 'V', '1257', 'R', 'U', '2093', 'x', '6877', 'c', '9219', 'Z', 'a', 9203, 'X', 'K', 2901, 'M', 'x']