POJ 1161

#include <iostream>
using namespace std;
const int maxn=30010;
int parent[maxn];
int amount[maxn];
int rank[maxn];
int n,m;
void init()
{
for(int i=0;i<n;i++)
{
parent[i]=i;
amount[i]=1;
rank[i]=0;
}
}
int find(int t)
{
if(parent[t]!=t)
return(find(parent[t]));
return t;
}
void Union(int r1,int r2)
{
if(rank[r1]>rank[r2])
{
parent[r2]=r1;
amount[r1]+=amount[r2];
}
else
{
parent[r1]=r2;
amount[r2]+=amount[r1];
if(rank[r1]==rank[r2])
rank[r2]++;
}
}
int main()
{
while(scanf("%d%d",&n,&m)&&!(n==0&&m==0))
{
init();
int i,j=0,g,f,r1,r2,t;
for(i=0;i<m;i++)
{
cin>>g;
if(g)
{
cin>>f;
for(j=1;j<g;j++)
{
cin>>t;
r1=find(f);
r2=find(t);
if(r1!=r2)
{
Union(r1,r2);
}
}
}
}
int outcome=find(0);
cout<<amount[outcome]<<endl;
}
return 0;
}