Detailed Instructions: 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.
Q: 19, 20, ['W', '6371', '5661', '2061', 'e', '8731', '121', '2097', 'Q', 'R', 'd', 'm', 'c', 'V', 'L', 'U', 'u', 'c', '7543', 'w', '8461', 'L', 'b', 'F', 'D', '4427', 'J', 'b', '4113', 'x']
A:
w3457