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: 7, 20, ['1217', '7769', 'Y', '2651', '249', 'L', '3173', 'c', 'W', '2453', 'e', '8209', 'n', '6353', 'U', '6629', 'Q', 'B', 'x', 'T', 'u', '2157', '4017', '8287', 'N', 'W', '5341', '9805', 'x']

TxBQ6629U6353n8209e2453Wc3173