Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

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

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	ans := make([][2]int, N)
	time := 0
	found := make(map[int]bool)
	var dfs func(cur int)
	dfs = func(cur int) {
		time++
		ans[cur][0] = time
		found[cur] = true
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if !found[next] {
				dfs(G[cur][i])
			}
		}
		time++
		ans[cur][1] = time
	}
	for i := 0; i < N; i++ {
		if !found[i] {
			dfs(i)
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprint(wtr, i+1)
		for j := 0; j < 2; j++ {
			fmt.Fprint(wtr, " ")
			fmt.Fprint(wtr, ans[i][j])
		}
		fmt.Fprintln(wtr)
	}
	wtr.Flush()
}

C++: #include <cstdio>
#include <cstring>
int g[101][101], d[101], f[101], vis[101];
int time = 0, n;

void dfs(int u)
{
  if (vis[u] != 0) return;
  vis[u] = 1;
  d[u] = ++time;
  for (int i = 0; i < n; i++)
  {
    if (g[u][i] == 1)
    {
      dfs(i);
    }
  }
  vis[u] = 2;
  f[u] = ++time;
}

int main()
{
  memset(g, 0, sizeof(g));
  memset(vis, 0, sizeof(vis));
  scanf("%d", &n);
  for (int i = 0; i < n; i++)
  {
    int u, adj_num;
    scanf("%d%d", &u, &adj_num);
    while (adj_num--)
    {
      int v;
      scanf("%d", &v);
      g[u - 1][v - 1] = 1;
    }
  }
  for (int i = 0; i < n; i++)
  {
    if (!vis[i]) dfs(i);
  }
  for (int i = 0; i < n; i++)
  {
    printf("%d %d %d\n", i + 1, d[i], f[i]);
  }
}

C++: #include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int INF = 1e9;

int d[105] = { -1 }, f[105] = { -1 };
int n = -1;
int mat[105][105] = { { 0 } };
int visited[105] = { 0 };

void dfs(int v, int& now)
{
  d[v] = now;
  visited[v] = 1;
  ++now;
  for (int u = 1; u <= n; ++u) {
    if (mat[v][u] && !visited[u]) {
      dfs(u, now);
    }
  }
  f[v] = now;
  ++now;
}

int main()
{
  fscanf(stdin, "%d", &n);
  for (int i = 0; i < n; ++i) {
    int u = -1, k = -1, v = -1;
    fscanf(stdin, "%d %d", &u, &k);
    for (int j = 0; j < k; ++j) {
      fscanf(stdin, "%d", &v);
      mat[u][v] = 1;
    }
  }
  int now = 1;
  for (int v = 1; v <= n; ++v) {
    if (!visited[v]) {
      dfs(v, now);
    }
  }
  for (int i = 0; i < n; ++i) {
    fprintf(stdout, "%d %d %d\n", i + 1, d[i + 1], f[i + 1]);
  }
  return 0;
}

C++: #include<iostream>
#include<stack>
//#include "stdio.h"

using namespace std;

#define N 100

#define WHITE 0
#define GRAY 1
#define BLACK 2
#define NIL -1

int n, M[N][N];
int color[N],d[N],f[N];
int world_time;

int next(int node){
  for(int v=0;v<n;v++){
    if(M[node][v] == 1 && color[v] == WHITE){
      return v;
    } 
  }
  return NIL;
}

void dfs_visit(int i){
  
  world_time = world_time + 1;
  stack<int> S;
  S.push(i);
  color[i] = GRAY;
  d[i] = world_time;

  int present,next_node;
  while( !S.empty() ){
    world_time = world_time + 1;
    present = S.top();
    next_node = next(present);

    if(next_node != NIL){
      S.push(next_node);
      d[next_node] = world_time;
      color[next_node] = GRAY;
    }else{
      color[present] = BLACK;
      S.pop();
      f[present] = world_time;
    }
  }
}

void dfs(){
  world_time = 0;

  for(int i=0;i<n;i++){
    color[i] = WHITE;
  }

  for(int i=0;i<n;i++){
    if(color[i] == WHITE){
      dfs_visit(i);
    }
  }

  for(int i=0;i<n;i++){
    cout << i+1 << " " << d[i] << " " << f[i] <<endl;
  }
}


int main(void){
  cin >> n;
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      M[i][j] = 0;
    }
  }

  int u,v,k;
  for(int i=0;i<n;i++){
    cin >> u >> k;

    for(int j=0;j<k;j++){
      cin >> v;
      M[u-1][v-1] = 1;
    }
  }

  dfs();

  return 0;
}

C++: #include<stdio.h>
#include<stack>
#include<string.h>
using namespace std;
int a[105][105];
int tim=0;
int first[105],last[105];
int zhuangtai[105];
int us;
int nex[105];
int findnext(int k)
{
    for(int i=nex[k];i<us;i++)
    {
        nex[k]=i+1;
        if(a[k][i]) return i;
    }
    return -1;
}
void visit(int k)
{
    for(int i=0;i<us;i++)
    {
        nex[i]=0;
    }
    stack<int > s;
    s.push(k);
    first[k]=++tim;
    zhuangtai[k]=1;
    while(!s.empty())
    {
        int n=s.top();
        int ne=findnext(n);
        if(ne!=-1)
        {
            if(zhuangtai[ne]==0){
                zhuangtai[ne]=1;
                first[ne]=++tim;
                s.push(ne);
            }
        }else{
            s.pop();
            zhuangtai[n]=2;
            last[n]=++tim;
        }
    }
}
void dfs()
{
    for(int i=0;i<us;i++)
    {
        zhuangtai[i]=0;
        nex[i]=0;
    }
    for(int i=0;i<us;i++)
    {
        if(zhuangtai[i]==0) visit(i);
    }
    for(int i=0;i<us;i++)
    {
        printf("%d %d %d\n",i+1,first[i],last[i]);
    }
}
int main()
{
    scanf("%d",&us);
    for(int i=0;i<us;i++)
    {
        int p,x;
        scanf("%d%d",&p,&x);
        p--;
        for(int j=0;j<x;j++)
        {
            int y;
            scanf("%d",&y);
            y--;
            a[p][y]=1;
        }
    }
    dfs();
    return 0;
}

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

int G[105][105]={};
int d[105]={},f[105]={};
int N,T=0;

void Gprint(int n){
    cout<<"\\|";
    for(int i=0; i<n; i++)cout<<i+1;
    cout<<endl;
    for(int i=0; i<n+2; i++)cout<<"-";
    cout<<endl;
    for(int i=0; i<n; i++){
        cout<<i+1<<"|";
        for(int j=0; j<n; j++){
            cout<<G[i][j];
        }
        cout<<endl;
    }
}

void dfs(int n){
    if(d[n])return;
    d[n]=++T;
    for(int i=0; i<N; i++){
        if(G[n][i])dfs(i);
    }
    f[n]=++T;
}

int main(){
    int u,k,v;

    cin>>N;
    for(int i=0; i<N; i++){
        cin>>u>>k;
        for(int j=0; j<k; j++){
            cin>>v;
            G[u-1][v-1]=1;
        }
    }

//    Gprint(N);

    for(int i=0; i<N; i++)
        dfs(i);

    for(int i=0; i<N; i++){
        cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
    }
}