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: 19, 20, ['w', '4131', 'C', '719', '2961', 'Q', '4167', '1001', 'p', '965', '1153', '6881', '3361', 'H', 'f', 'V', '9393', 'x', '6091', 'B', '6757', 'U', '2619', '5649', '6447', 'D']

SOLUTION: B1906

PROBLEM: 3, 4, ['6865', 'A', 's', 'o', '1989', 'i', '613', 'S', 's']

SOLUTION: os

PROBLEM: 1, 3, ['h', 'J', '111', 'Q', '9917', 'q', '1943']

SOLUTION:
111Jh