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, ['z', 'X', '1859', 'k', 'J', '1771', 'r', 'A', 'H', '5715', '9', '975', 'C', '59', '5943', 'w', '1841', 'h', 'F', '4561', 'j', 's', 'M']

j4561Fh1841w594359C97595715HAr