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, 16, ['M', '1253', 'L', '1997', 'E', 'u', '4953', '1627', '4497', '1839', 'M', 's', '9821', '9159', '845', '6189', 'F', 'G', 'E', '2303', '503']

SOLUTION: 981654895191289sM9381794472613594uE7991

PROBLEM: 1, 5, ['2861', '8639', '483', 'i', 'M', 'U', '6293', '5293', 'Q', 'y', '6117', '2335', 'g', 's', '4485', 's', 'o', 'P', 'O', '2745', '9817', '3335']

SOLUTION: Mi38493681682

PROBLEM: 15, 21, ['3209', '1111', '1819', 'o', 'b', '8067', 'N', 'V', 'X', 'g', '1735', '6117', '3955', '6361', 'i', 'r', 'e', 'J', 'k', 'i', 'R', 'D']

SOLUTION:
RikJeri