- Time limit: 1.00 s
- Memory limit: 512 MB
There are cities in Byteland but no roads between them. However, each day, a new road will be built. There will be a total of roads.
Your task is to process queries of the form: "after how many days can we travel from city to city for the first time?"
Input
The first input line has three integers , and : the number of cities, roads and queries. The cities are numbered .
After this, there are lines that describe the roads in the order they are built. Each line has two integers and : there will be a road between cities and .
Finally, there are lines that describe the queries. Each line has two integers and : we want to travel from city to city .
Output
For each query, print the number of days, or if it is never possible.
Constraints
Example
Input:
5 4 3 1 2 2 3 1 3 2 5 1 3 3 4 3 5
Output:
2 -1 4