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, 3, ['U', 'U', '5201', '4581', '2943', 'B', 'j']
answer:
1025U


question:
2, 5, ['f', 'd', '2691', 't', 'u']
answer:
ut1962d


question:
11, 14, ['a', '2279', '4947', '8507', '8701', '625', '8403', 'd', '4841', 'h', '833', 'F', 'L', 'Z', 'a', 'b', 'J', '803', 'L']
answer:

ZLF338