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]: 3, 21, ['V', '3661', '3743', 'Y', '3179', 'b', '7097', '3031', '5859', '4095', 'D', 'J', '2337', '4259', '2539', 'I', '9659', 'U', 'G', 'Q', '3145', '177', '9839', 'f']
[EX A]: 5413QGU9569I935295247332JD5904958513037907b9713Y3473

[EX Q]: 1, 2, ['Q', '6249', 'm', 'H', 'x', 'b', 'Z', 'z', '15']
[EX A]: 9426Q

[EX Q]: 9, 10, ['V', 'D', '9555', '4307', 'B', 'D', '1683', '5875', '6435', 's', '9847', 'm', '1903', 'b', '8679']
[EX A]:
s5346