- Time limit: 1.00 s
- Memory limit: 512 MB
Your task is to find out the maximum number of dance pairs and show how this number can be achieved.
The first input line has three integers $n$, $m$ and $k$: the number of boys, girls, and potential pairs. The boys are numbered $1,2,\dots,n$, and the girls are numbered $1,2,\dots,m$.
After this, there are $k$ lines describing the potential pairs. Each line has two integers $a$ and $b$: boy $a$ and girl $b$ are willing to dance together.
First print one integer $r$: the maximum number of dance pairs. After this, print $r$ lines describing the pairs. You can print any valid solution.
- $1 \le n,m \le 500$
- $1 \le k \le 1000$
- $1 \le a \le n$
- $1 \le b \le m$
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