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: 4, 20, ['4293', '7715', '9975', 'Y', 'g', '7299', '2101', '1661', '3245', '671', '5713', '4449', '4793', 'X', '4427', 'M', '3239', 'H', 'U', '3859', '6715']

3859UH3239M4427X4793444957136713245166121017299gY