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, 20, ['I', '5247', '9715', '1289', 'Y', 'n', 'C', '3633', 'w', 'o', '2507', 'D', 'r', 'W', '933', 'j', 'z', '1321', '7613', 'B', 'Y', 'B', 'm']

B76131321zj933WrD2507ow3633Cn