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, 6, ['643', 'X', 'F', '7453', '8495', '7943']

SOLUTION: 349759483547F

PROBLEM: 5, 5, ['8095', 'D', '9477', '9307', '9355', 'U', 'y', '5197', '2691', '3061']

SOLUTION: 5539

PROBLEM: 1, 4, ['F', '6727', '8177', 'X', '9681', 'B', 'W']

SOLUTION:
X77187276F