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:
3, 4, ['2419', '643', '8177', '7291', '561', '6529', '4101', 'u', '6445']
answer:
19277718


question:
6, 7, ['2289', '1015', 'T', 'e', '4499', 'J', 'B', '5107', 'x', '3103', 'Q', 'Z', 'H']
answer:
BJ


question:
6, 12, ['v', '2981', '3821', '631', '8463', 's', '6117', 't', 'S', '8863', '7815', 'r', '6615', '8921', '6403', '9389', 'x']
answer:

r51873688St7116s