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]: 2, 2, ['799', '3533', '7841']
[EX A]: 3353

[EX Q]: 3, 14, ['R', 'S', '8031', '5461', 'g', '3405', '2185', '7737', '8757', 'A', 'e', 'C', 'r', '7035', '4573', 'i', 'z', 'I', 'x', 'P', '7753', '107', 'l', 'Q', '6223', 'B', '1721']
[EX A]: 5307rCeA7578737758125043g16451308

[EX Q]: 6, 12, ['4999', '1799', '909', 'b', 'F', 'U', '6505', '4453', 'B', '651', 'k', '6595', '259', 'u', '5555']
[EX A]:
5956k156B35445056U