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, 6, ['e', 'w', '503', '2677', '4099', 'F', '4781', '3995', '8221', 'z', '6689', 'L', '3821', 'b', 'A', 'P', '4037', 'v', 'M', '3919']
[EX A]: F99047762305

[EX Q]: 4, 7, ['3421', '6129', '593', '203', '2731', '1393', '9739', '1087', '3453', '1389', 'W', 'D', 'b', '9261']
[EX A]: 937939311372302

[EX Q]: 8, 10, ['457', '503', '6985', '1497', '1667', '9431', '8991', 'k', 'G', 'L', 'm', 'S', 'a', 'c', '6913']
[EX A]:
LGk