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: 6, 21, ['O', 'y', 'w', 'm', '9421', '897', '8443', 'w', 'h', 't', 'v', '9145', 'y', '7531', '8431', 'Y', 'G', 'n', '7163', '5471', '6349', 'g', '1095', '8239', '1063', '8731', 'O', 'T', '5469']

634954717163nGY84317531y9145vthw8443897