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, 5, ['r', 'n', 'J', 'U', '3587', 'J', 'A', '9729', '2919', '1417', '2605', '2663', '9427', '4449', '8545', '8673', '3417', '5671', 'e', 'W', '6963', '6713', 'c', '5071', '2823']

SOLUTION: 7853

PROBLEM: 6, 13, ['a', 't', '3699', 'H', 'c', 'S', '2713', '5419', 'q', '7877', 'q', 'U', '833', '8411', '2003', '5373', 'P', '2913']

SOLUTION: 338Uq7787q91453172S

PROBLEM: 10, 11, ['9529', 'Y', '3641', '5291', 'j', 'l', '6291', 'a', '5169', 'P', '6749', '4377']

SOLUTION:
9476P