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: 5, 20, ['8881', 'y', 'C', '1983', 'U', '4637', 'G', 'v', 'M', '8349', 'r', '7889', '3129', '861', '2777', '3071', 'v', 'f', 'W', '285', 'R', '5373']

285Wfv3071277786131297889r8349MvG4637U