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.
9, 18, ['W', '3993', '4957', '1997', '4021', 'H', '7885', '5381', '5025', '3867', 'w', 'I', '5931', '3609', '851', 't', 'o', 'k', '5075', '6771', 'T', 'n', 'u', 'q', 'x', 'i', '1245']