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: 18, 20, ['D', 'O', '3411', '4875', '3605', '5573', '3039', 'S', '9617', '8743', 's', '9525', 'z', 's', 'O', 'y', 'Y', '9771', 't', '43', '5899', '2301', 'Z', 'O', 'O']

43t9771