TASK DEFINITION: In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.
PROBLEM: [621, 7677, 'b', '889', '6721', 'H', 'd', 'S'], [8151, 'F', 'b', '889', '6721', 'h', 4123]

SOLUTION: b, 889, 6721

PROBLEM: [2255, 4205, 'U', '7567', 'k', 5167], ['Q', 9439, 'U', '7567', 'H', 1307]

SOLUTION: U, 7567

PROBLEM: ['H', 191, 5269, 'I', 8869, 'N', 9617, 7679, 'C', '9103', '905', 'N', 'n', 'E', '1397', '1061', '4683', 'x', '5823', 'w', 'F', 'i', 'm', 'L', 5561], ['x', 2143, 2583, 'l', 781, 'i', 67, 7861, 'q', 7467, 8599, '9103', '905', 'N', 'n', 'E', '1397', '1061', '4683', 'x', '5823', 'w', 'F', 'y', 'G', 1961, 'V', 'B', 877, 'J', 6495, 3531]

SOLUTION:
9103, 905, N, n, E, 1397, 1061, 4683, x, 5823, w, F