Definition: In this task, you are given inputs i, j, and A, where i and j are integers and A is a list. You need to find all elements of A from the ith element to the jth element, reverse the order in which they occur, and then concatenate them to output the resultant 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 concatenate the elements and then reverse the string.
Input: 15, 20, ['G', 'G', 'K', '8477', 'N', 'D', '3609', 'e', '861', 'l', '1535', 's', 'z', '2897', '8513', '5777', 'a', 'Z', '569', '4489']

4489569Za57778513