You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
In this task, you are given two lists A,B. Find the longest common subsequence in the lists A and B.

[5797, 8817, '8297', 'b', 'U', 'b'], [5843, 8809, '8297', 'b', 'W', 'C']
Solution: 8297, b
Why? Here, '8297, b' is the longest common subsequence in both the input lists [5797, 8817, '8297', 'b', 'U', 'b'] and [5843, 8809, '8297', 'b', 'W', 'C'].

New input: [2221, 8015, 'q', 'f', 267, 'A', 'I', 7303, 4213, 8891, 511, 'Z', 4347, 'l', '4621', '507', '5189', 'q', 'k', '2185', '7731', 'm', '661', '4053', '4621', '8393', '5271', 'A', 'T', 9691, 'p', 2669], [2089, 5875, 2865, 'l', 4937, 'l', '4621', '507', '5189', 'q', 'k', '2185', '7731', 'm', '661', '4053', '4621', '8393', '5271', 'B', 'Q', 'q', 'C', 'e', 'A', 'i', 7783, 989]
Solution:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
l, 4621, 507, 5189, q, k, 2185, 7731, m, 661, 4053, 4621, 8393, 5271