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, 7, ['H', '689', 'd', '6759', '3531', 'd', '8393', 'N', 'd', 'o', '2377', '4065', '8021', 'c']
answer:
3938d13539576d


question:
13, 18, ['1931', '2101', 'U', '3395', '7549', '5187', '4669', '9151', '6971', '5793', '2173', '2279', 'h', 'w', 't', '4769', '6581', 'D']
answer:
D18569674twh


question:
16, 20, ['9715', 'O', '3397', '585', 'e', 'L', '7591', '6603', 'x', 'G', '9791', '1127', '5809', 'e', '8129', 'n', 't', '7977', 'X', 'b', 'z', '2307', '4547', 'U', 'H', '1511', '3807']
answer:

bX7797tn