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.
15, 19, ['J', 'v', 'z', '7537', '3715', '4367', 'K', '4145', 'Y', 'L', '3925', 'z', '6227', 'd', '9819', '1007', '4933', 'X', 'm', '9679', '9709', '721', '2187', 'u']