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: 5, 6, ['7319', 'U', 'Z', '1163', '8123', '4861', '117', '3893', '2489', 'S', '1511']

SOLUTION: 16843218

PROBLEM: 13, 17, ['k', 'f', 'C', '1551', 'Y', '2149', 'r', 'R', '5875', 'C', 'Y', '2145', 'O', 'b', 'M', 'y', '7407', 'X', '1227', 'F', 'n']

SOLUTION: 7047yMbO

PROBLEM: 6, 7, ['5229', 'A', 'P', 'D', '3667', 'Z', '4997', 'K', 's', 'I', 'A', '3327', '7421', '2259', 'T', 'n', 'w', '961', 'z', 'T', '6999']

SOLUTION:
7994Z