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: 11, 21, ['J', 'g', 'K', '1863', '5511', '6655', 'Q', '8357', 'X', '3215', 'h', '6807', 'c', 'K', 'n', '4327', '8279', '9431', 't', 'f', '4999', '4045', '6041', 'M', '6843']

4999ft943182794327nKc6807h