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, 21, ['D', '4567', 'P', '1629', '5717', 'L', '3493', 'g', '5449', 'P', 'Q', '3391', 'C', '5249', '4575', '4519', 'b', '6749', '9551', '7327', '8281']

8281732795516749b451945755249C3391QP5449g3493