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.
20, 25, ['W', '6191', '8529', '9317', 'c', '2571', 'l', 'n', '985', 'u', 'W', 'b', 'd', '7339', 'B', '3279', 't', '449', 'm', '7359', '8155', '2809', '973', '291', '3627', '713', 'u', '7113']