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

SOLUTION: os

PROBLEM: 19, 23, ['r', '521', '2357', 'j', 'R', 'a', '4853', 'q', '2383', 'i', '8071', '3715', '7533', '1407', 'e', '9495', 'k', '3789', 'P', 'c', '2565', 'q', '4565', 'P']

SOLUTION: 5654q5652cP

PROBLEM: 8, 21, ['F', 'Q', 'W', '5377', '6615', 'e', 'P', '8443', 'o', '6131', '5031', '8207', '6571', '7729', '1867', 'b', '2747', '6633', '7941', '783', '6363', 'G', '8753']

SOLUTION:
3636387149733667472b768192771756702813051316o3448