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: 16, 18, ['7121', 'b', 'P', '7771', 'l', 'I', '7817', '5185', '7989', 'H', '4449', '3859', '869', '9321', 'O', '6453', '6219', '8349', '5327', 'm', 'c', 'O', '1185', '2703', '9673', 'q']

SOLUTION: 943891263546

PROBLEM: 1, 2, ['3909', '5863', '707']

SOLUTION: 36859093

PROBLEM: 5, 6, ['7417', '8545', '1429', '5113', 'g', '351', '6385', 'W', 'L', 's', '1249', '2447', '6363']

SOLUTION:
153g