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.

[EX Q]: 7, 18, ['4879', '857', 'X', '8629', 'K', 'l', 'U', '5611', '5989', '4439', '4897', 'D', 'p', '8109', 'F', 'a', '4665', 'Q']
[EX A]: Q5664aF9018pD7984934498951165U

[EX Q]: 6, 7, ['J', '701', 'm', '8837', 'b', 'd', '5911', 'y', '8031']
[EX A]: 1195d

[EX Q]: 6, 6, ['x', 'o', '4399', '1001', '9267', 'U', 'r', 'e', '6415', '3811', '5385', 'v', 'E', 'q', '6033', 'm', 'i', 'O', 'W', 'R', '4017', 'I', 'T', 'D', '1349', '7213', '9619']
[EX A]:
U

