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: 2, 18, ['8671', 'd', '5109', '1915', 'h', '2777', '3087', '9861', '8597', 'P', '4505', 'j', 'M', 'O', 's', 'Q', '2703', 'X', 'l', 'g', '1801']

SOLUTION: X3072QsOMj5054P7958168978037772h51919015d

PROBLEM: 12, 12, ['c', 'a', 'G', 't', '753', 'x', 'I', '4479', 'i', 'y', 'J', 'w']

SOLUTION: w

PROBLEM: 16, 19, ['751', 'i', 'o', '7179', '4071', 'y', '4389', 'U', 'e', 'L', '6485', '5891', 'D', '8905', '3871', 'i', 'B', '3139', 'r', 'W', '9493', 'X', 'R', '3623', 'O', 'k', 'B', '7445', 'c']

SOLUTION:
r9313Bi