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: 5, 7, ['2725', '1489', 'P', '2021', 'c', '1605', 'R', 'T', 'p', 'q', '6487', '3395', 'u', 'x']

SOLUTION: R5061c

PROBLEM: 1, 8, ['7991', '7999', '8575', '4211', '6003', '2483', '7877', '7249', 'K', '21']

SOLUTION: 94277787384230061124575899971997

PROBLEM: 1, 2, ['I', 'Q']

SOLUTION:
QI