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<iostream>
#include<map>
#include<vector>
#include<algorithm>
#include<cmath>
#include<climits>
#include<ctime>
#include<cstring>
#include<stack>
#include<queue>
#include<sstream>
#include<string>

#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl;


using namespace std;

int main()
{

  while(1){

    int n;
    cin >> n;

    if(n==0) break;

    vector<vector <int> > data;

    rep(i,n){
      int m;
      vector<int> tmp;
      cin >> m;
      rep(j,m){
        int p;
        cin >> p;
        tmp.push_back(p);
      }
      data.push_back(tmp);
    }

    int k,l;
    vector<int> k_data;
    cin >>k;
    rep(i,k){
      cin >> l;
      k_data.push_back(l);
    }

    bool flag[n];
    int count=0;
    rep(i,n){
      flag[i]=true;count++; 
      if(data[i].size()==0){flag[i]=false;count--; continue;}
      rep(j,k_data.size()){
        int a = lower_bound(data[i].begin(),data[i].end(),k_data[j])-data[i].begin();
        //cout << a << endl;
        //cout << i << " " << j << endl; 
        if(data[i][a]!=k_data[j]){ flag[i]=false; count--;break;}
      }
    }


    if(count==1){
      rep(i,n){ if(flag[i]) cout << i+1 << endl;}
    }else{
      cout << -1 << endl;
    } 
  }
}

C++: #include<iostream>
#include<vector>
using namespace std;

const int MAX_N = 101;

bool know[MAX_N][MAX_N];
int leaked[MAX_N];

void sovle(int N) {
    for (int i = 1; i <= N; i++) {
        for (int j = 1; j <= N; j++) {
            know[i][j] = false;
        }
    }
    int M, p;
    for (int i = 1; i <= N; i++) {
        cin >> M;
        for (int j = 0; j < M; j++) {
            cin >> p;
            know[i][p] = true;
        }
    }
    int K;
    cin >> K;
    for (int i = 0; i < K; i++) {
        cin >> leaked[i];
    }
    vector<int> ans;
    for (int i = 1; i <= N; i++) {
        bool is_ok = true;
        for (int j = 0; j < K; j++) {
            if (!know[i][leaked[j]]) {
                is_ok = false;
                break;
            }
        }
        if (is_ok) ans.push_back(i);
    }
    if (ans.size() == 1) cout << ans[0] << endl;
    else cout << -1 << endl;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N;
    while (true) {
        cin >> N;
        if (N == 0) break;
        sovle(N);
    }
    return 0;
}

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

using namespace std;

set<int> product(set<int> &a, set<int> &b)
{
    set<int> ret;

    for (set<int>::iterator it = b.begin(); it != b.end(); it++)
        if (a.find(*it) != a.end())
            ret.insert(*it);

    return ret;
}

int main()
{
    int n;

    while (cin >> n, n) {
        vector<set<int> > mem(n);
        int k, l, cnt = 0;
        
        for (int i = 1; i <= n; i++) {
            int m, p;
            
            cin >> m;
            while (m--) {
                cin >> p;

                mem[p - 1].insert(i);
                
            }
        }

        cin >> k;
        cin >> l;

        set<int> ans = mem[l - 1];
        k--;
        while (k--) {
            cin >> l;
            ans = product(ans, mem[l - 1]);
        }
        
        int leak;
        for (set<int>::iterator it = ans.begin(); it != ans.end(); it++) {
            cnt++;
            leak = *it;
        }

        if (cnt == 1)
            cout << leak << endl;
        else
            cout << -1 << endl;
    }

    return 0;
}

C++: #include <cstdio>
#include <iostream>
using namespace std;

int main(){
	while(1){
		int n;
		bool know[100][100]; //構成員firstはsecondの情報を持つか
		
		for(int i=0; i<100; ++i)
		for(int j=0; j<100; ++j)
		know[i][j]=false;
		
		scanf(" %d", &n);
		if(n==0) break;
		for(int i=0; i<n; ++i){
			int m;
			scanf(" %d", &m);
				
			for(int j=0; j<m; ++j){
				int p;
				scanf(" %d", &p);
				know[i][p]=true; //iはpの情報を知っている
			}
		}	
		
		int k, list[100];
		scanf(" %d", &k);
		for(int i=0; i<k; ++i) scanf(" %d", &list[i]);
		
		int ans=-1;
		for(int i=0; i<n; ++i){
			bool flag=true;
			
			for(int j=0; j<k; ++j){
				if(!know[i][list[j]]){
					flag=false;
					break;
				}	
			}	
			
			if(flag){
				if(ans==-1) ans=i+1;
				else{ //複数いる
					ans=-1;	
					//printf("db\n");
					break;
				}
			}
		}
		
		printf("%d\n", ans);
	}
	return 0;
}