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, ['9421', 'Q', '4849', '8137', '7871', 'S', 'd', 'U', '9411', 'p', '781', '4969', 'm', '5291', '5427', '5219', '1525', 'I', 'Y', 'e', 'N']

NeYI1525521954275291m4969781p9411Ud