TASK DEFINITION: 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.
PROBLEM: 7, 18, ['4879', '857', 'X', '8629', 'K', 'l', 'U', '5611', '5989', '4439', '4897', 'D', 'p', '8109', 'F', 'a', '4665', 'Q']

SOLUTION: Q5664aF9018pD7984934498951165U

PROBLEM: 3, 18, ['R', '7241', 'A', 'z', '8115', '6251', 'F', '1405', 'N', '3567', '1525', 'a', '6057', 'E', '5637', '4969', '3499', '5489', 'Z', 'K', 'M', 'I', 'Z', 'j']

SOLUTION: 9845994396947365E7506a52517653N5041F15265118zA

PROBLEM: 7, 10, ['6041', 'j', '8733', '1731', '4725', '3991', '4165', 'z', '2953', 'u', 'J']

SOLUTION:
u3592z5614