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