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: 20, 21, ['D', 'Z', 'z', '5407', '5653', 'l', 'g', '9989', '3933', '3545', '1849', 'x', 'D', '4951', 'R', 'o', '3285', 'v', '6019', 'I', '7717', '8899', '9781', '2493', 'u']

7717I