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: 5, 18, ['w', '1165', 'k', 'P', 'u', '437', '3969', '8015', '8887', 'e', '6989', '4483', 'a', '2231', '3645', 'p', 'X', 'U', '6667', 'G', 'H', 'H', '7661']

UXp36452231a44836989e888780153969437u