- Time limit: 1.00 s
- Memory limit: 512 MB
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.
Input
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.
Output
Print the length of the shortest route for each query. If there is no route, print -1 instead.
Constraints
- 1 \le n \le 500
- 1 \le m \le n^2
- 1 \le q \le 10^5
- 1 \le a,b \le n
- 1 \le c \le 10^9
Example
Input:
4 3 5 1 2 5 1 3 9 2 3 3 1 2 2 1 1 3 1 4 3 2
Output:
5 5 8 -1 3