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, 20, ['4861', '8577', '495', 'n', '4957', 'G', 'b', '8545', 'n', 'G', 'b', 'T', '1597', 'f', '9645', 'Y', 'f', '803', 'B', '153']

153B803fY9645f1597TbGn8545bG4957