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: 5, 7, ['Y', '5101', 'B', '5129', 'a', 'y', 'v', '4577', '5455', '6685', '6435']

SOLUTION: vya

PROBLEM: 2, 13, ['o', 'B', '5117', 'h', '3007', '2037', 'j', '2651', 'b', 'b', '8977', 'v', 'U', 'l', '3949', 'e', 'x', '6539', '3663', '1359', '2851']

SOLUTION: Uv7798bb1562j73027003h7115B

PROBLEM: 1, 1, ['6415', '939', '9249', '2037']

SOLUTION:
5146