There are $n$ cities and $m$ roads between them. Your task is to process $q$ queries where you have to determine the length of the shortest route between two given cities.
The first input line has three integers $n$ , $m$ and $q$ : the number of cities, roads, and queries.
Then, there are $m$ lines describing the roads. Each line has three integers $a$ , $b$ and $c$ : there is a road between cities $a$ and $b$ whose length is $c$ . All roads are two-way roads.
Finally, there are $q$ lines describing the queries. Each line has two integers $a$ and $b$ : determine the length of the shortest route between cities $a$ and $b$ .
Print the length of the shortest route for each query. If there is no route, print $-1$ instead.
4 3 5 1 2 5 1 3 9 2 3 3 1 2 2 1 1 3 1 4 3 2· · \n · · \n · · \n · · \n · \n · \n · \n · \n · \n
5 5 8 -1 3\n \n \n \n \n