TLE!!!求调！

#include<iostream>
using namespace std;
int a[5002][5002];
int ans=0;
bool flag[5002];
void dfs(int k){
    if(a[k][0]==0){
        return;
    }
    for(int i=1;i<=a[k][0];i++){
    	if(flag[a[k][i]]) continue;
    	//cout<<a[k][i]<<endl;
        flag[a[k][i]]=1;
        dfs(a[k][i]);
        ans++;
    }
}
int main(){
    int n;
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i][0];
        for(int j=1;j<=a[i][0];j++){
            cin>>a[i][j];
        }
    }
    //cout<<endl;
    //cout<<1<<endl; 
    flag[1]=1;
    dfs(1);
    //cout<<endl;
    cout<<ans+1;
    return 0;
}