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, 2, ['k', 'A', '2153']

SOLUTION: Ak

PROBLEM: 7, 9, ['s', '3175', '1431', 'a', 'u', '7265', 'N', 'H', '1217', 'x', 'u', 'a', 'c', 'n', 'b', 'J', 'B', '6907', 'D', '6691', 'N', '7959', 'm']

SOLUTION: 7121HN

PROBLEM: 8, 13, ['1271', 'I', 'j', 'g', 'w', '4041', '4781', 'S', 'J', '5627', 'Y', 'c', '5157', '6013', 'M', 'h']

SOLUTION:
7515cY7265JS