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: 2, 19, ['5231', 'X', '5781', '7999', 'l', 'z', '8891', '1835', '9963', 'S', 's', '2537', 'o', 'm', '7239', 'y', '3803', '3765', '1393', '8397', 'U', 'n', 'I']

139337653803y7239mo2537sS996318358891zl79995781X