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++: /*
 * 2399.cc: Save Your Privacy!
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100;

typedef long long ll;

const int INF = 1 << 30;
const ll LINF = 1LL << 60;

/* typedef */

typedef vector<int> vi;
typedef queue<int> qi;
typedef pair<int,int> pii;
typedef bitset<MAX_N> bsn;

/* global variables */

bsn ps[MAX_N];

/* subroutines */

/* main */

int main() {
  for (;;) {
    int n;
    cin >> n;
    if (n == 0) break;

    for (int i = 0; i < n; i++) ps[i].reset();

    for (int i = 0; i < n; i++) {
      int m;
      cin >> m;
      for (int j = 0; j < m; j++) {
	int pj;
	cin >> pj;
	pj--;
	ps[i].set(pj);
      }
      //printf("ps[%d]=", i); cout << ps[i].to_string() << endl;
    }

    bsn bls(0);
    int k;
    cin >> k;
    for (int i = 0; i < k; i++) {
      int li;
      cin >> li;
      li--;
      bls.set(li);
    }
    //cout << "bls=" << bls.to_string() << endl;

    int an = 0, ai = -1;
    
    for (int i = 0; i < n; i++)
      if ((bls & ps[i]) == bls) an++, ai = i;

    printf("%d\n", (an == 1) ? ai + 1 : -1);
  }

  return 0;
}

C++: #include "bits/stdc++.h"
#define int long long
#define range(i, a, b) for(int i = (a); i < (b); i++)
#define rep(i, a) range(i, 0, a)
#define all(a) (a).begin(),(a).end()
using namespace std;
const int INF = sizeof(int) == sizeof(long long) ? 1000000000000000000LL : 1000000000;
const int MOD = 1000000007;
const long double EPS = 1e-8;
using vi = vector <int>;
using vvi = vector <vi>;

signed main() {
	int n;
	while(cin >> n, n){
		vvi m(n, vi(0));
		rep (i, n) {
			int sz; cin >> sz;
			int p;
			rep (j, sz) {
				cin >> p;
				m[i].push_back(p);
			}
		}
		int k; cin >> k;
		vi l(k);
		string pear = "", berry = "";
		rep (i, k){
			cin >> l[i];
			pear += "0";
			berry += "1";
		}
		int cnt = 0;
		int ans = -1;
		rep (i, n) {
			string comp = pear;
			rep (j, m[i].size()) {
				rep (va, k) {
					if (m[i][j] == l[va]) {
						comp[va]++;
					}
				}
			}
			if (comp == berry) {
				cnt++;
				ans = i + 1;
			}
		}
		if(cnt == 1)
			cout << ans << endl;
		else
			cout << -1 << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

//repetition
#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define rep(i, n) for(ll i = 0; i < (ll)(n); i++)

//container util
#define all(x) (x).begin(),(x).end()

//typedef
typedef long long ll;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<ll> VLL;
typedef vector<VLL> VVLL;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;

//const value
//const ll MOD = 1e9 + 7;
//const int dx[] = {0,1,0,-1};//{0,0,1,1,1,-1,-1,-1};
//const int dy[] = {1,0,-1,0};//{1,-1,0,1,-1,0,1,-1};

//conversion
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
inline ll toLL(string s) {ll v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}


int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;

  while(true){
      cin >> n;
      if(n == 0) break;
      vector<map<int,bool>> p(n);
      rep(i,n){
        int m;
        cin >> m;
        rep(j,m){
          int x;
          cin >> x;
          x--;
          p[i][x] = true;
        }
      }
      int k;
      cin >> k;
      VI l(k);
      rep(i,k){
        cin >> l[i];
        l[i]--;
      }
      VI ans;
      rep(i,n){
        bool flag = true;
        rep(j,k){
          if(p[i][l[j]] == false) flag = false;
        }
        if(flag) ans.push_back(i+1);;
      }
      if(ans.size() == 1) cout << ans.back() << endl;
      else cout << -1 << endl;
  }
  return 0;
}

C++: #include<vector>
#include<stack>
#include<queue>
#include<cstring>
#include<cstdio>
#include<cmath>
using namespace std;

#define rep(i,n) for(int i=0;i<n;i++)
#define REP(n) rep(i,n)

const int MAXN = 101, MAXK = 101;

int n,m,k,t,p,l;
bool joho[MAXN][MAXN];
bool still[MAXN];

int main()
{
    while(cin >> n && n)
    {
        memset(still, true, sizeof(still));
        memset(joho, false, sizeof(joho));
        int ans = -1;
        int num = 0;
        for(int i=1;i<=n;i++)
        {
            cin >> t;
            rep(j,t)
            {
                cin >> p;
                joho[i][p] = true;
            }
        }

        cin >> k;
        rep(j,k)
        {
            cin >> l;
            for(int i = 1;i<=n;i++) still[i] = still[i] & joho[i][l];
        }

        for(int i=1;i<=n;i++)if(still[i])
        {
            ans = i;
            num++;
        }
        if(num>=2 || num == 0) {cout << -1 << endl; continue;}
        else cout << ans << endl;

    }

    return 0;
}