POJ 1611 The Suspects

/***********************************
Problem: POJ 1611 The Suspects
Time: 16MS
Memory: 276K
Accepted Time: 2009-08-19 20:26:36
Tip:  并查集
http://hi.baidu.com/fandywang_jlu/blog/item/b49e40893ddbb0b00f244485.html
************************************/
#include <stdio.h>
int pre[30000];
void Init(int n)
{
	for(int i=0;i<n;i++)pre[i]=-1;
}
int Find(int x)
{
	int p=x;
	while(pre[p]>0)p=pre[p];
	while(p!=x)
	{
		int temp=pre[x];
		pre[x]=p;
		x=temp;
	}
	return x;
}
void Union(int x,int y)
{
	int a=Find(x),b=Find(y);
	if(a==b)return;
	if(pre[a]<pre[b])pre[a]+=pre[b],pre[b]=a;
	else pre[b]+=pre[a],pre[a]=b;
}
int main()
{
	int n,m;
	while(scanf("%d%d",&n,&m),n+m!=0)
	{
		if(m==0)
		{
			printf("1/n");
			continue;
		}
		Init(n);
		int i,n2,t1,t2;
		while(m--)
		{
			scanf("%d",&n2);
			scanf("%d",&t1);
			for(i=1;i<n2;i++)
			{
				scanf("%d",&t2);
				Union(t1,t2);
			}
		}
		printf("%d/n",-pre[Find(0)]);
	}
	return 0;
}