zoj 1789

#include <iostream>
#include <stdio.h>
using namespace std;

int group[30000];
int find(int x)
{
while(group[x]>=0)//==0编号从0开始的！！在这个地方一直错最后才发现
x=group[x];

return x;
}
void Union(int x,int y)
{
int r1=find(x);
int r2=find(y);
if(r1!=r2)
{int  temp=group[r1]+group[r2];
if(group[r1]<group[r2])
{
group[r1]=r2;
group[r2]=temp;
}
else
{
group[r2]=r1;
group[r1]=temp;
}
}

}
int main()
{
int n,m,i;
//	freopen("1.txt","r",stdin);
while(~scanf("%d%d",&n,&m))
{
if(n==0&&m==0)break;
for(i=0;i<n;i++)
group[i]=-1;
while(m--)
{
int k;
scanf("%d",&k);
int fa;
for(i=0;i<k;i++)
{ int t;
scanf("%d",&t);
if(i==0)
fa=t;
else
if(i!=0)
{
Union(fa,t);
}

}

}

int s=find(0);
cout<<-group[s]<<endl;
}

return 0;
}