In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.

[621, 7677, 'b', '889', '6721', 'H', 'd', 'S'], [8151, 'F', 'b', '889', '6721', 'h', 4123]
b, 889, 6721

[7395, 'b', 'k', 4085, 2295, 'W', 'e', 'd', '1583', '9993', 'x', '2291', '1847', 'R', 'a', 'n', 'r', 'G', '7947', '6081', 'H', 'K', 't', '6537', 'q', 'V', '3423', '9531', '4907', '123', '4757', 'J', 'S', 'Q', 'D', 'f', 4941, 6655, 8343, 2509, 6487, 'b', 'E', 'f', 'n', 'v', 'j', 7091, 9231, 9129, 7785, 9709, 2645, 3179, 'U', 631, 7891], [7807, 8461, 'n', 'C', 9827, 1359, 'O', 3781, 'k', 'n', 'F', 'l', 'x', 'O', 4867, 'd', '1583', '9993', 'x', '2291', '1847', 'R', 'a', 'n', 'r', 'G', '7947', '6081', 'H', 'K', 't', '6537', 'q', 'V', '3423', '9531', '4907', '123', '4757', 'J', 'S', 'Q', 'D', 'H', 'B', 'f', 'X', 2529, 2153, 'u', 'z', 747, 5899, 1307, 'l', 'Q', 'x', 3787, 'b', 1187, 'h', 9519, 3483, 'q']
d, 1583, 9993, x, 2291, 1847, R, a, n, r, G, 7947, 6081, H, K, t, 6537, q, V, 3423, 9531, 4907, 123, 4757, J, S, Q, D

['d', 'I', 'C', '4669', 'C', '7143', 'O', 7483, 'C', 7647], [5057, 2391, 2633, 'C', '4669', 'C', '7143', 'v', 'D', 2609, 1903]

C, 4669, C, 7143