Q: In this task, you are given inputs 'i', 'j', and A, where 'i' and 'j' are integers and A is a list. A list is shown by two brackets and comma-separated numbers and characters inside, like ['1', '12', 'l']. You need to concatenate all elements of A from the ith element to the jth element, and then reverse the resulting 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 reverse first and then concatenate.
8, 21, ['2381', '5057', 'o', 'M', '7495', '3787', '3877', '5055', '6055', '4145', 'v', 'O', 'K', '361', 'X', 'H', '357', 'H', '7553', 'S', 'R', 'H', '5973']
A:
RS3557H753HX163KOv541455065505