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: 15, 18, ['3799', 'l', '635', '5947', 'k', '903', '6377', '6433', 'E', 't', 'G', 'n', 'D', '2633', '4729', 'e', 'e', '6321', '671', 'L']

6321ee4729