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;





int main(){
  while(1){


  
  int n;
  cin>>n;
  if(n==0){break;}
  int p;
  int a[1000][1000]={};
  for(int i=0;i<=n;i++){
    int m;
    cin>>m;
    a[i][0]=m;
    for(int t=1;t<=m;t++){
      cin>>a[i][t];
    }
    sort(&a[i][1],&a[i][m+1]);
  }
  
  int c=0,list[10000]={};
  for(int i=0;i<n;i++){
    for(int t=1;t<=a[i][0];t++){
      if(a[n][1]<a[i][t]){break;}
      if(a[n][1]==a[i][t]){list[c]=i; c++;}
    }
  }

  for(int i=1;i<=a[n][0];i++){
    for(int k=0;k<c;k++){
      if(list[k]==-1){break;}
      bool j=true;
      for(int t=1;t<=a[list[k]][0];t++){
	if(a[n][i]==a[list[k]][t]){j=false; break;}
	if(a[n][i]<a[list[k]][t]){break;}
      }
	if(j){list[k]=-1;}
    }
  }
    
    int count=0;
    int ans=-1;
    for(int k=0;k<c;k++){
      if(list[k]!=-1){ans=list[k]+1; count++;}
      if(count>=2){ans=-1; break;}
    }

    cout<<ans<<endl;

  



  }
    
  return 0;
}

C++: #include <iostream>
using namespace std;
int N,M,p[101][101],K,l[101],a[101][101];
//double dx,dy,dz,sx,sy,sz,a,b,c,p,q,r;
//long long int l[51],sum;
//double t,lt;
int main(){
    while(1){
        cin >>N ;
        if (N == 0)break;

        for(int i=1;i<=100;i++){
            for(int j=1;j<=100;j++){
                a[i][j] = 0;
            }
        }

        for(int i=1;i<=N;i++){
            cin >> M;
            for (int j=1;j<=M;j++){
            cin >>p[i][j];
            a[i][p[i][j]] = 1;
            }
        }
        cin >> K ;
        for (int i=1;i<=K;i++){
            cin >> l[i];
        }
        int cnt = 0;
        int ans = -1;
        for (int i=1;i<=N;i++){
            int know = 1;
            for (int j=1;j<=K;j++){
                know = know *  a[i][l[j]];
            }
            if (know ==  1){
                cnt++;
                ans = i;
            }

        }
        if(cnt >1)ans = -1;
        cout <<ans <<endl;
    }

}

C++: #include<bits/stdc++.h>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define pb(a) push_back(a)
#define all(a) (a).begin(), (a).end()
#define debug(x) cout << "debug " << x << endl;
using namespace std;

int checkDataList(int data[105][105],bool fdn[105], int fd, int p){
    int sum = 0;
    for(int i = 0; data[p][i] != -1; i++){
        sum+=fdn[data[p][i]];
    }
    if(sum == fd) return 1;
    else return 0;
}

int main(){
    int n;
    while(cin >> n, n){
        int data[105][105];
        rep(i,105) rep(j,105) data[i][j] = -1;
        rep(i,n){
            int haveData;
            cin >> haveData;
            rep(j,haveData){
                cin >> data[i][j];
            }
        }
        int flowData;
        bool flowDataNumber[105] = {0};
        cin >> flowData;
        rep(i,flowData){
            int input;
            cin >> input;
            flowDataNumber[input] = 1;
        }
        int ansCheck[2] = {0};
        rep(i,n){
            int x = checkDataList(data, flowDataNumber, flowData, i);
            ansCheck[0]+=x;
            if(x) ansCheck[1] = i + 1;
        }
        if(ansCheck[0] == 1) cout << ansCheck[1] << endl;
        else cout << -1 << endl;
    }
}

C++: #include "bits/stdc++.h"
#define pb push_back
#define all(a) (a).begin(),(a).end()
#define rep(i, n) for(int i=0;i<(n);++i)
#define rrep(i, n) for(int i=n-1;i>=0;--i)
#define debug(x) cout << #x << " : " << x << " ------------ " << endl;
using namespace std;
using Info = tuple<int, int>;
int main()
{
    int n;
    while (cin >> n, n) {
        map<int, vector<int>> pList;
        rep (i, n) {
            int m;
            cin >> m;
            rep (j, m) {
                int p;
                cin >> p;
                if (!pList.count(p)) {
                    pList[p] = vector<int>{i+1};
                } else {
                    pList[p].pb(i+1);
                }
            }
        }
        int k;
        cin >> k;
        vector<int> lList = vector<int>();
        rep (i, k) {
            int l;
            cin >> l;
            lList.pb(l);
        }
        map<int, int> counter;
        for (auto l : lList) {
            if (!pList.count(l)) {
                break;
            }
            for (auto p : pList[l]) {
                if (!counter.count(p)) {
                    counter[p] = 1;
                } else {
                    counter[p] += 1;
                }
            }
        }
        vector<int> result = vector<int>();
        for (auto c : counter) {
            if (c.second == lList.size())
                result.pb(c.first);
        }
        if (result.size() != 1)
            cout << -1 << endl;
        else
            cout << result[0] << endl;
    }
    
    return EXIT_SUCCESS;
}