TASK DEFINITION: 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.
PROBLEM: 2, 3, ['N', 'U', 'D', 'm', '9001', 'I', '2675', 'l', '2771', 'U', '1181', 'U']

SOLUTION: DU

PROBLEM: 18, 20, ['5263', '7963', '8931', 'I', 'n', '8167', 'A', '5429', 'O', '6539', '7303', 'V', 'l', 'd', 's', '8377', 'Z', '7345', 'X', 'D', '6125', 'c', 'o', 'x', 'I', '2807', '3995', '3297', 'O']

SOLUTION: DX5437

PROBLEM: 14, 15, ['5055', 'b', 'I', '2323', 'T', 'A', 'c', 'Q', '3815', '7435', '3213', '1657', '3513', 'z', '2033', 'm', 's']

SOLUTION:
3302z