Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()

	for {
		N := io.NextInt()
		if N == 0 {
			break
		}
		set := make([]map[int]struct{}, N)
		for i := 0; i < N; i++ {
			set[i] = make(map[int]struct{})
			M := io.NextInt()
			for j := 0; j < M; j++ {
				p := io.NextInt()
				set[i][p] = struct{}{}
			}
		}
		K := io.NextInt()
		l := make([]int, K)
		for i := 0; i < K; i++ {
			l[i] = io.NextInt()
		}

		ans := 0
	FOR_OUTER:
		for i := 0; i < N; i++ {
			for j := 0; j < K; j++ {
				if _, f := set[i][l[j]]; f == false {
					continue FOR_OUTER
				}
			}
			switch ans {
			case 0:
				ans = i + 1
			default:
				ans = -1
			}
		}
		if ans > 0 {
			io.Println(ans)
		} else {
			io.Println(-1)
		}
	}
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int INF = 1e9;
const ll LINF = 1e18;
template<class S,class T> ostream& operator << (ostream& out,const pair<S,T>& o){ out << "(" << o.first << "," << o.second << ")"; return out; }
template<class T> ostream& operator << (ostream& out,const vector<T> V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; }
template<class T> ostream& operator << (ostream& out,const vector<vector<T> > Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; }
template<class S,class T> ostream& operator << (ostream& out,const map<S,T> mp){ out << "{ "; for(auto it = mp.begin(); it != mp.end(); it++){ out << it->first << ":" << it->second; if(mp.size()-1 != distance(mp.begin(),it)) out << ", "; } out << " }"; return out; }

/*
 <url:>
 問題文============================================================
 =================================================================
 解説=============================================================
 ================================================================
 */
int N;
int solve(){
    int res = 0;
    vector<vector<int>> G(N);
    for(int i = 0; i < N;i++){
        int M; cin >> M;
        for(int j = 0; j < M;j++){
            int p; cin >> p; p--;
            G[p].push_back(i);
        }
    }
    vector<int> f(N);
    int K; cin >> K;
    for(int i = 0; i < K;i++){
        int l; cin >> l; l--;
        for(auto p:G[l]){
            f[p]++;
        }
    }
    //  for(auto v:f) cout << v << " "; cout << endl;
    if(count(f.begin(),f.end(),K) != 1) return -1;
    return res = (int)(find(f.begin(),f.end(),K) - f.begin()) + 1;
}
int main(void){
    cin.tie(0); ios_base::sync_with_stdio(false);
    while(cin >> N,N){
        cout << solve() << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

int main()
{
	for(int n;cin>>n,n;){
		vector<vector<int>> p(n);
		for(int i=0;i<n;i++){
			int m; cin>>m;
			p[i].resize(m);
			for(int j=0;j<m;j++)
				cin>>p[i][j];
		}
		int k; cin>>k;
		vector<int> l(k);
		for(int i=0;i<k;i++)
			cin>>l[i];
		
		for(int i=0;i<n;i++)
			sort(p[i].begin(),p[i].end());
		sort(l.begin(),l.end());
		
		vector<int> c;
		for(int i=0;i<n;i++)
			if(includes(p[i].begin(),p[i].end(),l.begin(),l.end()))
				c.push_back(i);
		
		if(c.size()==1)
			cout<<c[0]+1<<endl;
		else
			cout<<-1<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<string>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<queue>
#include<vector>
#include<cmath>
#include<cstring>
#include<utility>
#include<set>
#include<stack>
#include<complex>
#define vi vector<int>
#define vvi vector<vector<int> >
#define ll long long int
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vb vector<bool>
#define vc vector<char>
#define vs vector<string>
#define ld long double
#define INF 1e9
#define EPS 0.0000000001
#define rep(i,n) for(int i=0;i<n;i++)
#define CC puts("-------ok--------");
#define all(in) in.begin(), in.end()
#define bv vector<bool>
using namespace std;
typedef pair<int, int>PI;
using namespace std;
#define MAX  999999
int main(){
    int n;
    while(cin>>n,n){
        vvi v(100,vi()); vi u(100,0);
        rep(i,n){
            int temp; cin>>temp;
            rep(j,temp){int a;cin>>a; v[a].push_back(i);};
        }
        int temp; cin>>temp;
        rep(i,temp)cin>>u[i];
        bool check = false; int ans = 0;
            int cnt = 0;
            rep(i,temp){
                if(v[u[i]].empty()) break;
                cnt++;
                if(v[u[i]].size() == 1){check = true;ans = v[u[i]].back();}
                }
        if(cnt != temp) check = false;
        if(check) cout << ans+ 1<< endl;
        else cout << -1 << endl;
    }
}

C++: #include<iostream>
#include<string>
using namespace std;
int p[100][100];
int main(){
	int n,m[100];
	int k,l[100];
	while(true){
	cin>>n;
	if(n==0)
		break;
	for(int i=0;i<n;i++){
		cin>>m[i];
		for(int j=0;j<m[i];j++){
			cin>>p[i][j];
		}
	}
	cin>>k;
	for(int i=0;i<k;i++)
		cin>>l[i];
	int count=0,set;
	for(int i=0;i<n;i++){
		bool t=true;
		for(int j=0;j<k;j++){
			bool f=false;
			for(int o=0;o<m[i];o++){
				if(l[j]==p[i][o])
					f=true;
			}
			if(f==false)
				t=false;
		}
		if(t==true){
			if(count==0){
				set=i;
			}
			count++;
		}
	}
	if(count==1)
		cout<<set+1<<endl;
	else
		cout<<"-1"<<endl;
	}
	return 0;
}