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 <cstdio>
#include <cassert>
#include <iostream>
#include <sstream>
#include <algorithm>
#include <numeric>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <array>

using namespace std;

#define all(c) begin(c), end(c)
#define dump(c) cerr << "> " << #c << " = " << (c) << endl
#define REP(i, a, b) for (int i = (a); i < (int)(b); i++)
#define rep(i, n) REP(i, 0, n)

typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;

const int INF = 1001001001;
const double EPS = 1e-10;


template<typename T1,typename T2>
ostream& operator<<(ostream& os, const pair<T1,T2>& p){
  return os << '(' << p.first <<',' << p.second << ')';
}
template<typename T>
ostream& operator<<(ostream& os, const vector<T>& a){
  os << '[';
  rep(i,a.size()) os << (i ? " " : "") << a[i];
  return os << ']';
}

int main() {
  for(int N; cin >> N, N != 0; ) {
    bitset<100> ps[100];
    rep(i, N) {
      int M; cin >> M;
      rep(j, M) {
        int p; cin >> p;
        ps[i][p - 1] = 1;
      }
    }
    bitset<100> ls;
    int K; cin >> K;
    rep(i, K) {
      int l; cin >> l;
      ls[l - 1] = 1;
    }

    int cnt = 0;
    int ans = -1;
    rep(i, N) {
      if ((ps[i] | ls) == ps[i]) {
        cnt++;
        ans = i;
      }
    }

    if (cnt == 1) cout << ans + 1 << endl;
    else cout << -1 << endl;
  }
  
  return 0;
}

C++: #include <string>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <vector>
#include <queue>
#include <set>
#include <utility>
#include <algorithm>
#include <numeric>
#include <iostream>
#include <iterator>
#include <sstream>

using namespace std;

int N;
bool p[100][100];

int main()
{
	while(cin>>N,N){
		for (int i = 0; i < N; i++){
			int m; cin>>m;
			for (int j = 0; j < m; j++){
				int x; cin>>x;
				x--;
				p[i][x] = true;
			}
			p[i][i] = true;
		}
		int k; cin>>k;
		vector<int> l(k);
		for (int i = 0; i < k; i++){ cin>>l[i]; l[i]--;}

		int ans = -1;
		for (int i = 0; i < N; i++){
			int j;
			for (j= 0; j< k; j++){
				if(!p[i][l[j]]) break;
			}
			if(j == k){
				if(ans == -1){
					ans = i + 1;
				} else {
					ans = -1; break;
				}
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <functional>
#include <set>
#include <sstream>
#include <map>
#include <queue>

using namespace std;

int main()
{
	int n;
	while(cin>>n,n){
		vector< vector<int> > info(n);
		for(int i=0;i<n;i++){
			int m;
			cin>>m;
			info[i].resize(m);
			for(int j=0;j<m;j++) cin>>info[i][j];
			sort(info[i].begin(),info[i].end());
		}

		int k;
		cin>>k;
		vector<int> out(k);
		for(int i=0;i<k;i++) cin>>out[i];

		vector<int> ans;
		for(int i=0;i<n;i++){
			bool ok=true;
			for(int j=0;j<k && ok;j++) ok=binary_search(info[i].begin(),info[i].end(),out[j]);
			if(ok) ans.push_back(i+1);
		}

		if(ans.size()==1) cout<<ans[0]<<endl;
		else cout<<-1<<endl;

	}

	return 0;
}

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

int main(){
  bool p[110][110];
  int n,l[110],m,t;

  while(scanf("%d",&n),n){
    for(int i=1;i<=n;i++){
      for(int j=1;j<=n;j++)p[i][j] = false;
      l[i] = false;

      scanf("%d",&m);
      for(int j=0;j<m;j++){
	scanf("%d",&t);
	p[i][t] = true;
      }
    }

    scanf("%d",&m);
    for(int i=0;i<m;i++){
      scanf("%d",&t);
      l[t] = true;
    }

    int ans = -1;
    for(int i=1;i<=n;i++){
      bool f = true;
      for(int j=1;j<=n;j++){
	if(l[j] && !p[i][j]){
	  f = false; break;
	}
      }
      if(f){
	if(ans < 0)ans = i;
	else{
	  ans = -1; break;
	}
      }
    }
    printf("%d\n",ans);
  }
}

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

#define rep(i, n) for(int i = 0; i < (n); i++)
#define repp(i, l, r) for(int i = (l); i < (r); i++)
#define per(i, n) for(int i = ((n)-1); i >= 0; i--)
#define perr(i, l, r) for(int i = ((r)-1); i >= (l); i--)
#define all(x) (x).begin(),(x).end()
#define MOD 1000000007
#define IINF 1000000000
#define LINF 1000000000000000000
#define SP <<" "<<
#define CYES cout<<"Yes"<<endl;
#define CNO cout<<"No"<<endl;

typedef long long LL;
typedef long double LD;

int main(){
  while(1){
    int n;
    cin >> n;
    if(n==0) return 0;
    vector<vector<bool>> e(n,vector<bool>(n,false));
    rep(i,n){
      int m;
      cin >> m;
      int x;
      rep(j,m){
        cin >> x;
        e[i][x-1]=true;
      }
    }
    int k,x;
    cin >> k;
    vector<int> r(k);
    rep(i,k){
      cin >> r[i];
      r[i]--;
    }
    vector<int> ans;
    rep(i,n){
      rep(j,k){
        if(!e[i][r[j]]){
          goto next;
        }
      }
      ans.push_back(i);
      next:;
    }
    if(ans.size()==1){
      cout << ans[0]+1 << endl;
    }else{
      cout << -1 << endl;
    }
  }
  return 0;
}

C++: #include <set>
#include <vector>
#include <algorithm>
#include <cstdio>
using namespace std;

int main(){
	int x,n,m,k,i;
	for(;scanf("%d",&n),n;){
		vector<set<int> >v;
		for(i=0;i<n;i++){
			set<int>s;
			for(scanf("%d",&m),k=0;k<m;k++)
				scanf("%d",&x),s.insert(x);
			v.push_back(s);
		}
		set<int>t;
		for(scanf("%d",&k),m=0;m<k;m++)
			scanf("%d",&x),t.insert(x);
		vector<int>w;
		for(k=0;k<n;k++){
			set<int>s;
			set_intersection(v[k].begin(),v[k].end(),t.begin(),t.end(),inserter(s,s.end()));
			if(s.size()==t.size())w.push_back(k);
			if(w.size()>1)break;
		}
		printf("%d\n",w.size()==1?w[0]+1:-1);
	}
}