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, 7, ['2725', '1489', 'P', '2021', 'c', '1605', 'R', 'T', 'p', 'q', '6487', '3395', 'u', 'x']

SOLUTION: R5061c

PROBLEM: 7, 14, ['j', '2199', '6995', 't', 'U', 'C', '1589', '7061', '851', 'N', '7923', '7387', '2053', 'L', 'y', '3685', 'X', 'C', '4679', '3691', '2991', 'f']

SOLUTION: L350278373297N15816079851

PROBLEM: 1, 5, ['2497', 'l', '9871', '3665', '469']

SOLUTION:
96456631789l7942