[AcWing 4267] 可疑人员

#include<bits/stdc++.h>

using namespace std;

typedef long long LL;

const int N = 1e6 + 10;

int n, m;
int a[N];
int p[N];

struct Node
{
    int x, y;
} s[N];

int find(int x)
{
    if (p[x] != x)
        p[x] = find(p[x]);
    return p[x];
}

void merge(int a, int b)
{
    if (a == b)
        return;
    int pa = find(a), pb = find(b);
    p[pa] = pb;
}

void solve()
{
    while (cin >> n >> m, n) {
        for (int i = 0; i < n; i ++)
            p[i] = i;
        while (m --) {
            int k;
            cin >> k;
            for (int i = 0; i < k; i ++) {
                cin >> a[i];
                merge(a[i], a[0]);
            }
        }
        int res = 0;
        for (int i = 0; i < n; i ++)
            if (find(i) == find(0))
                res ++;
        cout << res << endl;
    }
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    solve();

    return 0;
}