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: 17, 21, ['5503', '2979', '6307', '633', 'n', '9339', '5829', '5291', '8967', 'i', '9063', '975', 'G', '9187', '3227', 'A', '3487', '8187', 'H', '6097', 'H']

SOLUTION: H7906H78187843

PROBLEM: 3, 8, ['6945', '2403', '7633', '2933', '1015', 'G', '7261', '9101', '6435', 'M']

SOLUTION: 10191627G510133923367

PROBLEM: 3, 10, ['k', 'k', 'a', 'd', '1139', '2191', 'P', 'Q', 'w', '291', 'V', '4785', '1621', '3725']

SOLUTION:
192wQP19129311da