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: 18, 19, ['r', '8611', 'b', 'R', 'p', 'W', '8021', 'x', '1153', '985', 'W', '7913', '8263', 'l', 'p', 'X', 'w', 'Z', '6635']

6635Z