instruction:
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.
question:
7, 9, ['s', '3175', '1431', 'a', 'u', '7265', 'N', 'H', '1217', 'x', 'u', 'a', 'c', 'n', 'b', 'J', 'B', '6907', 'D', '6691', 'N', '7959', 'm']
answer:
7121HN


question:
3, 9, ['7671', '575', 'l', '989', '7015', 'X', 'x', '3543', '3771', '905', '3815', 's']
answer:
17733453xX5107989l


question:
3, 5, ['z', '3471', 'H', '3703', 'M']
answer:

M3073H