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:
2, 2, ['G', 'S']
answer:
S


question:
4, 12, ['H', 'r', 'n', 'Y', '173', '9285', '3105', '883', 'n', '8915', '6923', 'S', 'T', 'o', '1639', '8421', 'g']
answer:
S32965198n38850135829371Y


question:
14, 21, ['H', 'v', 'Y', 'R', '2689', 'W', 'h', '3519', 'a', '8529', 'u', 'q', '4247', '1469', '8497', '2873', '9963', '5037', '4287', 'f', 'q', 't', 'B', 'k']
answer:

qf782473053699378279489641