In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
['i', 'x', 997, 'L', 'Q', 4945, 2335, 3749, 'm', 4981, 'U', 1333, 'M', 'i', 1669, 'S', 'q', 'u', 'S', '6757', '7353', '4909', 't', 'T', 'o', '3637', '6639', 'z', 'L', '293', '6601', 'H', '3893', 'y', 'C', 'a', '7529', 'q', 'L', 'f', 'y', 521], [4275, 9463, 'Y', 'p', 8175, 'd', 6369, 2881, 5041, 8459, 'M', 5495, '6757', '7353', '4909', 't', 'T', 'o', '3637', '6639', 'z', 'L', '293', '6601', 'H', '3893', 'y', 'C', 'a', '7529', 'q', 'L', 'f', 'b', 'n', 'I', 'm', 'f', 'q', 'Y', 9625]