Given the task definition and input, reply with output. In this task, you are given inputs 'i', 'j', and A, where 'i' and 'j' are integers and A is a list. A list is shown by two brackets and comma-separated numbers and characters inside, like ['1', '12', 'l']. You need to concatenate all elements of A from the ith element to the jth element, and then reverse the resulting string. 'i' and 'j' will be non-negative, and will always have a value less than the length of A. 'i' will always be less than 'j'. Perform the operations in order, i.e., do not reverse first and then concatenate.

8, 20, ['931', '8373', '1465', 'L', 'w', '7315', '3215', '2179', 's', '4767', 'V', '4177', '8987', '1685', '903', 'U', '2499', 'p', '8987', 'w', 'O', '1405', '9539', '2309', 'q', 'o', '5715', 'k', 'Y', 'b']

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
w7898p9942U309586178987714V7674s9712