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: 12, 21, ['A', 'M', '7909', 'r', 'u', '6633', '1343', 'E', '1173', 'y', 'h', 'f', 'c', '8463', '9711', '9561', '5061', 'd', '6477', 'n', '8863']

8863n6477d5061956197118463cf