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: 4, 6, ['w', '8785', '2921', 'J', 'P', 'g', '9273', '5439', 'O', 'F', 'u', '967', '9007']

SOLUTION: gPJ

PROBLEM: 3, 3, ['H', '7843', '2823', '529']

SOLUTION: 3282

PROBLEM: 15, 18, ['z', 'y', 'J', '4017', 'v', 'i', '341', 'G', '3305', 'q', 'U', 'l', 'T', 'T', '3859', 'O', '6755', 'b', '6583', '777', '9449', '2037', 'N', '2609', '8279', 'y', '6411']

SOLUTION:
b5576O9583