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: 1, 5, ['M', 'H', '7813', '6149', 'u', 't', '3643', '5901', 'A', 'g', '3929', 'V']

SOLUTION: u94163187HM

PROBLEM: 1, 1, ['Q', '2357', '6479', '7105', 'M', 'x', '6281', '9331', 'z', 't', 'N', 'O', 'n', 'K', '9575', 'w', '657', '8531', '8837', 'p', '7781']

SOLUTION: Q

PROBLEM: 2, 21, ['Y', '5507', 'R', '471', '1875', '21', '2759', '8765', 'z', 'Z', 'Q', 'G', '8397', '3477', 'N', '6807', 'T', 's', 'z', '3761', 'J', 'J', 'W', 'E', 'k', 'y', '6913', '5135']

SOLUTION:
J1673zsT7086N77437938GQZz56789572125781174R7055