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: 6, 18, ['n', 'B', 'Y', 'c', '7657', '8735', '8629', '5813', 'f', 'h', 'J', 'U', '7137', 'O', '7487', '1597', 'd', '963', '5581', '6733', '9181', 'e', '3203', 'v', '9999', '8791', 'y', 'r', 'O', '5687']

963d15977487O7137UJhf581386298735