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: 1, 5, ['7115', '3109', '3805', '6831', '6897', 'y', 'b']

SOLUTION: 79861386508390135117

PROBLEM: 5, 11, ['4381', '7607', '3995', '7639', 'W', '2377', '2639', 'Z', 'D', '4511', 'K', '3211', '6939', 'n', 'J', 'd', '9647']

SOLUTION: K1154DZ93627732W

PROBLEM: 8, 13, ['D', 'N', '9497', 'G', '5163', '1059', '1441', '5737', 'O', '3765', 'x', 'J', '8807', '6049', '6871', '3673', 'M']

SOLUTION:
7088Jx5673O7375