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: 7, 8, ['637', '2587', 'U', 'R', '6883', 'I', '6643', '4971', '2691', '2439', 'H', 'U', '7111', '873']

49716643