80pts求调玄关

#include<bits/stdc++.h>
#define ll long long
#define db double
#define endl '\n'
#define int register int
#define AKIOI ios::sync_with_stdio(false);cin.tie(0),cout.tie(0)
#define AKNOI return 0
using namespace std;
ll n,k,indeg[505];
vector<ll>v[505];
queue<ll>q;
signed main(){
	AKIOI;
	cin>>n;
	for(int i=1;i<=n;i++){
		ll x,m,y;
		cin>>x>>m;
		for(int j=1;j<=m;j++){
			cin>>y;
			v[x].push_back(y);
			indeg[y]++;
		}
	}
	for(int i=1;i<=n;i++){
		if(indeg[i]==0){
			q.push(i);
		}
	}
	while(!q.empty()){
		ll now=q.front();
		k++;
		q.pop();
		for(auto it:v[now]){
			indeg[it]--;
			if(indeg[it]==0){
				q.push(it);
			}
		}
	}
	if(k==n) cout<<"YES"<<endl;
	else cout<<n-k<<endl;
	AKNOI;
}