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, 7, ['4403', 'D', '635', '8957', '1637', 'n', '4021', 'b', 'H', 'e', 'H', '1651', '1207', '7447', '9975', '6777', '5907', 'u', '9981', '5271', 'T']

4021n16378957