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 <iostream>
#include <vector>
#include <numeric>

using namespace std;

vector<vector<int32_t>> A(101);
vector<int32_t> d(101), f(101);
int32_t t = 1;

void dfs(int32_t u) {
    d[u] = t++;

    for (int32_t v : A[u]) {
        if (d[v] == 0) {
            dfs(v);
        }
    }

    f[u] = t++;

    return;
}

int main() {
    fill(d.begin(), d.end(), 0);

    int32_t n;
    cin >> n;

    for (int32_t i = 0; i < n; i++) {
        int32_t u, k;
        cin >> u >> k;

        for (int32_t j = 0; j < k; j++) {
            int32_t v;
            cin >> v;

            A[u].push_back(v);
        }
    }

    dfs(1);

    for (int32_t i = 1; i <= n; i++) {
        cout << i << " " << d[i] << " " << f[i] << endl;
    }

    return 0;
}

C++: #define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>

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



using namespace std;




int main() {
	
	int n;
	cin>>n;
	vector<vector<int>>t(n,vector<int>(0));
	for(int i=0;i<n;i++){
		int x,r;cin>>r>>x;
		for(int j=0;j<x;j++){
			int w;cin>>w;w--;t[i].push_back(w);
			//t[w].push_back(i);
		}
		sort(t[i].begin(),t[i].end());
	}/*
	for(int i=0;i<n;i++){
		sort(t[i].begin(),t[i].end());
		for(int j=0;j<t[i].size();j++)cout<<t[i][j];
		cout<<endl;
	}
	*/
	stack<int>S;
	bool F[105]={};
	S.push(0);
	int p=1;
	F[0]=1;
	vector<int>G(n),H(n);
	int g=1;
	G[0]=1;
	
	while(S.size()||p<n){
		g++;
		if(!S.size()){
			
			for(int i=1;i<n;i++)
				if(!F[i]){
					F[i]=1;
					S.push(i);
					G[i]=g;
					p++;
					break;
				}
			//	cout<<t[S.top()].size();
			//break;
				

		}
		else{
		
		//cout<<p;
		int v=S.top();
		int a=-1;
		for(int i=0;i<t[v].size();i++){
			if(!F[t[v][i]]){
				a=t[v][i];break;
			}
			//if(v==2)cout<<t[v][i]<<"&"<<F[i];
		}
		//cout<<a;
		//if(v==2&&a==-1)break;
		if(a==-1){
			H[S.top()]=g;
			S.pop();
			
			
		}
		else{
			//cout<<"%"<<a<<endl;
			F[a]=1;
			G[a]=g;
			S.push(a);
			p++;
		}
		}
	}
	/*for(int i=0;i<t[S.top()].size();i++)
		cout<<t[S.top()][i];
	cout<<"#"<<t[S.top()][1];
	*/
	for(int i=0;i<n;i++){
		cout<<i+1<<" "<<G[i]<<" "<<H[i]<<endl;
	}
	

	
	return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;
int t;
vector<int> G[110], d(110), f(110);

void dfs(int u) {
    d[u] = ++t;
    for (int v: G[u]) {
        if (d[v] == 0) dfs(v); 
    }
    f[u] = ++t; 
}

int main() {
    int n; cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k; cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v; cin >> v;
            G[u-1].push_back(v-1);
        }
    }
    for (int u = 0; u < n; u++) {
        if (d[u] == 0) dfs(u);
    }
    for (int u = 0; u < n; u++) {
        cout << u+1 << " " << d[u] << " " << f[u] << endl; 
    }
}

C++: #include <iostream>
#include <stack>
using namespace std;
static const int N=101;
static const int White=0;
static const int Gray=1;
static const int Black=2;

int M[N][N];
int d[N],nt[N],f[N],tt,color[N];
int n;
int next_v(int k){
  for(int i=nt[k];i<=n;i++){
    nt[k]=i+1;
    if(M[k][i]) return i;
  }
  return -1;
}
void dfs_visit(int r){
  stack<int> S;
  S.push(r);
  color[r]=Gray;
  d[r]=++tt;

  while(!S.empty()){
    int u=S.top();
    int v=next_v(u);
    if(v!=-1){
      if(color[v]==White){
        d[v]=++tt;
        S.push(v);
      }
    }else{
      S.pop();
      color[u]=Black;
      f[u]=++tt;
    }
  }
}
void dfs(){
  tt=0;
  for(int i=1;i<=n;i++){
    if(color[i]== White)dfs_visit(i);
  }
  for(int i=1;i<=n;i++){
    cout<<i<<" "<<d[i]<<" "<<f[i]<<"\n";
  }
}
int main(){
  cin>>n;
  for(int i=0;i<n;i++){
    int u,k,v;
    cin>>u>>k;
    for(int j=0;j<k;j++){
      cin>>v;
      M[u][v]=1;
    }
  }
  dfs();
}