Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve

const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 最初にiを訪問した時刻。発見時刻
//f[i]: iの隣接リストを訪問し終えた時刻。完了時刻
var color, d, f [MAX]int

func dfs_visit(u int) {
	color[u] = GRAY
	time++
	d[u] = time
	//隣接を調べる
	for v := 0; v < n; v++ {
		if M[u][v] == 0 {
			continue
		}
		//隣接するvが、未訪問だった場合
		if color[v] == WHITE {
			dfs_visit(v)
		}
	}
	//訪問完了処理
	color[u] = BLACK
	time++
	f[u] = time
	//訪問完了
}

func dfs() {
	//初期化
	for u := 0; u < n; u++ {
		color[u] = WHITE
	}
	time = 0

	//未訪問のuを始点として、深さ優先探索
	for u := 0; u < n; u++ {

		if color[u] == WHITE {
			dfs_visit(u)
		}
	}

	for u := 0; u < n; u++ {
		fmt.Println(u+1, d[u], f[u])
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	dfs()

}

C++: // ALDS1_11_B
#include <bits/stdc++.h>
#define endl "\n"
#define rep(i,n) for(int i=0;i<int(n);i++)
#define SZ(x) ((int)(x).size())
#define all(x) (x).begin(),(x).end()
using namespace std;
typedef long long ll;
template <class T>ostream &operator<<(ostream &o,const vector<T>&v)
{o<<"{";for(int i=0;i<(int)v.size();i++)o<<(i>0?", ":"")<<v[i];o<<"}";return o;}
namespace you {
    std::string to_string(char val) {
        return std::string(1, val);
        // return std::string{val};
        // you::to_string(char)
    }
}

vector<vector<int>> node(101);
vector<int> setu(101);
vector<bool> seen(101,false); 
vector<int> start(101,0);
vector<int> goal(101,0);
int t=0;
void dfs(int x){
    if(seen[x]==true) return;
    seen[x]=true;
    t++;
    start[x]=t;
    rep(i,setu[x]){
        dfs(node[x][i]);
    }
    t++;
    goal[x]=t;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(12);

    int n;
    cin>>n;
    rep(i,n){
        int u,k;
        cin>>u>>k;
        rep(j,k){
            int v;
            cin>>v;
            node[u].push_back(v);
            setu[u]=k;
        }
    }
    for(int i=1;i<=n;i++){
        dfs(i);
    }
    for(int i=1;i<=n;i++){
        cout<<i<<" "<<start[i]<<" "<<goal[i]<<endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define repr(i, n) for (int i = (n); i >= 0; --i)
#define FOR(i, m, n) for (int i = (m); i < (n); ++i)
#define FORR(i, m, n) for (int i = (m); i >= (n); --i)
using namespace std;
typedef long long ll;
const ll mod = 1000000007;
const ll mod2 = 998244353;
const int INF = 1000000005;
const int MAX = 105;

int t = 0;
pair<int, int> ans[MAX];
bool seen[MAX];
vector<int> to[MAX];

void dfs(int u) {
  if (seen[u]) return;
  seen[u] = true;
  ans[u].first = ++t;
  for (int v: to[u]) {
    dfs(v);
  }
  ans[u].second = ++t;
}

int main() {
  int n, u, k, v;
  cin >> n;
  rep(i, n) {
    cin >> u >> k;
    rep(j, k) {
      cin >> v;
      to[u].push_back(v);
    }
  }

  rep(i, n+1) seen[i] = false;
  FOR(i, 1, n+1) sort(to[i].begin(), to[i].end());

  FOR(i, 1, n+1) dfs(i);

  FOR(i, 1, n+1) {
    cout << i << " " << ans[i].first << " " << ans[i].second << endl;
  }



  
  return 0;
}

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

int main()
{
 int i;
}

C++: #include <bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
#define SIZE 200005
#define INF 1000000005LL
//#define INF 1e18
#define MOD 1000000007

using namespace std;
typedef long long int ll;
typedef pair <int,int> P;

int c;
vector<int> E[SIZE];
int d[SIZE],f[SIZE]; //init:0

void dfs(int v){
  c++;
  d[v]=c;
  for(int to : E[v]) if(d[to] == 0){
    dfs(to);
  }
  c++;
  f[v] = c;
}

int n;

int main(){
  cin >> n;
  rep(i,0,n){
    int v,k;
    cin >> v >> k;
    rep(i,0,k){
      int u;
      cin >> u;
      //E[u].push_back(v);
      E[v].push_back(u);
    }
  }

  rep(i,0,n){
    if(d[i+1] ==0) dfs(i+1);
  };

  rep(i,0,n){
    cout << i+1 << " " <<  d[i+1] << " " << f[i+1] << endl;
  }

  return 0;
}

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

int main(){
  vector <vector<int> > path_field;
  int n;

  cin >> n; n++;
  path_field.resize(n);
  for(int i=1;i<n;i++){
    path_field[i].resize(n);
    for(int j=1;j<n;j++){
      path_field[i][j]=0;
    }
  }
  for(int i=1;i<n;i++){
    int _m,m;

    cin >> _m >> m;
    for(int j=0;j<m;j++){
      int to;
      
      cin >> to;
      path_field[i][to]=1;
    }
  }

  vector <tuple<int,int> > ans;
  deque <int> stk;
  int sarched_point,sum=0;

  ans.resize(n);
  for(int i=1;i<n;i++){
    ans[i]=make_tuple(0,0);
  }
  for(int i_=1;i_<n;i_++){
    if(get<0>(ans[i_])==0){
      stk.push_back(i_);
      if(sum!=0) sum++;
    }
  
    while(!stk.empty()){
      sarched_point = stk.back();
      sum++;

      if(get<0>(ans[sarched_point])==0){
        get<0>(ans[sarched_point])=sum;
      }
      for(int i=1;i<n;i++){
        if((path_field[sarched_point][i]==1)&&(get<0>(ans[i])==0)){
          stk.push_back(i);
       	  break;
        }else if(i==(n-1)){
          get<1>(ans[sarched_point])=sum+1;
          stk.pop_back();
        }
      }
    }
  }

  for(int i=1;i<n;i++){
    cout << i << " " << get<0>(ans[i]) << " " << get<1>(ans[i]) << endl;
  }
}

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

vector<int> *a;
bool *check;
int *d,*f;

int dfs(int u, int time){
    int i, v;
    check[u] = true;
    d[u] = time;
    time++;
    for(i=0;i<a[u].size();i++){
        v = a[u][i];
        if(!check[v])time = dfs(v,time);
    }
    f[u] = time;
    time++;
    return time;
}

int main(){
    int i, j, n, u, k, v;
    scanf("%d",&n);
    check = (bool *)malloc(sizeof(bool)*(n+1));
    d = (int *)malloc(sizeof(int)*(n+1));
    f = (int *)malloc(sizeof(int)*(n+1));
    for(i=0;i<=n;i++)check[i] = false;
    a = (vector<int> *)malloc(sizeof(vector<int>)*(n+1));

    for(i=1;i<=n;i++){
        scanf("%d %d",&u,&k);
        for(j=0;j<k;j++){
            scanf("%d",&v);
            a[u].push_back(v);
        }
    }

    int time = 1;
    for(i=1;i<=n;i++){
        if(!check[i])
        time = dfs(i,time);
    }

    for(i=1;i<=n;i++)printf("%d %d %d\n",i,d[i],f[i]);

    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> P;
#define rep(i,n) for(int i=0;i<n;++i)
#define MOD (int) 1e9+7

vector<int> E[200];
int d[200]={}, f[200]={};

int func(int pos, int time){
    if(d[pos]>0){
        return time;
    }
    d[pos] = time;
    time++;
    for (int to : E[pos]){
        time = func(to, time);
    }
    f[pos] = time;
    time++;
    return time;
}

int main(){
    int n;
    cin >> n;
    rep(i, n){
        int u, k;
        cin >> u >> k;
        rep(j, k){
            int v;
            cin >> v;
            E[u].push_back(v);
        }
    }
    int time = 1;
    for (int i = 1; i <= n; i++){
        if(d[i]==0){
            time = func(i, time);
        }
        cout << i << " " << d[i] << " " << f[i] << endl;
    }
    // printf("%d\n", N);
    return 0;
}