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, ['Z', 's', '5399', '1205', '6471', 'r', '8519', 'U', 'n', '97', 'F', '4905', 'E', 'J', '9125', '7801', 'W', 'W', '5509', 'E', 'm', 'T']

mE5509WW78019125JE4905