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, 21, ['f', 'z', '8979', 'c', '3577', '9177', '1169', 'X', '1513', '6751', 'b', 'F', 'Y', '7751', 'l', 'R', '8083', '2479', '5597', '5583', 'H', '6927']

H558355972479