图论 --- MST

#include<iostream>
using namespace std;

int father[30001];

int find_father(int x)
{
    if(father[x]!=x)
        return find_father(father[x]);
    return x;
}

int main()
{
    int n, m;
    int k;
    int i, j;
    int x, y;
    while(cin>>n>>m)
    {
        if(n==0 && m==0)
            break;
        if(m == 0)
        {
            cout << "1\n";
            continue;
        }
        for(i=0;i<=n;i++)
            father[i]=i;
        for(i=0;i<m;i++)
        {
            cin>>k;
            cin>>x;
            for(j=1;j<k;j++)
            {
                cin>>y;
                int p = find_father(x);
                int q = find_father(y);
                if(p!=q)
                    father[p]=q;
                x = y;
            }
        }
        int cnt=0;
        int f = find_father(0);
        for(i=0;i<n;i++)
        {
            if(find_father(i)==f)
                cnt++;
        }
        cout<<cnt<<endl;
    }
    return 0;
}