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 <algorithm>
#include <iostream>
#include <unordered_map>
#include <vector>


using namespace std;

int timecount = 0;

void dfs(int cur, int u, bool* visited, int* timearray, int* timearray_end, unordered_map<int, vector<int> > mymap);

int main(){
  int u, i, id, k, j;
  cin >> u;
  unordered_map<int, vector<int> > mymap;

  for (i = 0; i < u; ++i){
    cin >> id >> k;
    vector<int> points;
    for (j = 0; j < k; ++j){
      int a;
      cin >> a;
      points.push_back(a);
    }
    mymap[id] = points;
  }
  
  bool visited[u+1];
  for (j = 1; j <= u; ++j){
    visited[j] = false;
  }
  visited[1] = true;

  int timearray[u+1];
  for (j = 1; j <= u; ++j){
    timearray[j] = 0;
  }
  int timearray_end[u+1];
  for (j = 1; j <= u; ++j){
    timearray_end[j] = 0;
  }

  dfs(1, u, visited, timearray, timearray_end, mymap);

  for (j = 1; j <= u; ++j){
    cout << j << " " << timearray[j] << " " << timearray_end[j]<< endl;
  }

}

void dfs(int cur, int u, bool* visited, int* timearray, int* timearray_end, unordered_map<int, vector<int> > mymap){
  timecount++;
  timearray[cur] = timecount;

  for(int i = 1; i <= u; ++i){
    
    if((i!=cur)&&(find(mymap[cur].begin(), mymap[cur].end(), i) != mymap[cur].end())&&(!visited[i])){
      visited[i] = true;
      dfs(i, u, visited, timearray, timearray_end, mymap);
    }
  }
  timecount++;

  timearray_end[cur] = timecount;
}

C++: #include<cstdio>
#include<vector>
#include<algorithm>
#include<utility>
#include<numeric>
#include<iostream>
#include<array>
#include<string>
#include<sstream>
#include<stack>
#include<queue>
#include<list>
#define _USE_MATH_DEFINES

#include<math.h>
#include<map>

#define SENTINEL 1000000001

#define min(a,b) (a)>(b)?(b):(a)
#define max(a,b) (a)>(b)?(a):(b)

using namespace std;

int G[101][101];
int d[101];
int f[101];
bool checked[101];

void explore(int id, int n,int& t)
{
	if (checked[id])
	{
		return;
	}
	checked[id] = true;
	d[id] = t;
	t++;

	for (int i = 1; i <= n; i++)
	{
		if (G[id][i] == 1)
		{
			explore(i, n,t);
		}
	}

	f[id] = t;
	t++;
}

int main()
{
	int n;
	cin >> n;

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

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

	int t = 1;
	explore(1, n, t);

	for (int 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;
int visit[111],d[111],f[111],t;
//    訪問状態 　　発見　　　完了
int n,M[111][111];
static const int WHITE=0; //未訪問
static const int GRAY=1; //訪問はした
void dfs(int u){
  visit[u]=GRAY; //訪問はした
  d[u]=++t; //発見した時刻
  for(int v=0;v<n;v++){
    if(M[u][v]==0) continue; //辺がない
    if(visit[v]==WHITE) dfs(v);
  }
  f[u]=++t; //訪問完了時刻
}
int main(){
  int u,v,k;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>u>>k;
    u--;
    for(int j=0;j<k;j++){
      cin>>v;
      v--;
      M[u][v]=1;
    }
  }
  for(int i=0;i<n;i++){
    if(visit[i]==WHITE) dfs(i); //訪問してないか... iを始点に
  }
  for(int i=0;i<n;i++){
    cout<<i+1<<' '<<d[i]<<' '<<f[i]<<endl;
  }
  return(0);
}

C++: #include <bits/stdc++.h>
#define rep(i, start, end) for (long long i = start; i < end; ++i)
#define srt(x) sort((x).begin(), (x).end());
#define rsrt(x) sort((x).rbegin(), (x).rend());
#define deb(x) cout<<#x<<" = "<<(x)<<" (L"<<LINE<<")"<<endl;
#define vdeb(x) {cout<<#x<<" = { "; rep(i, x.size()) cout<<x[i]<<' '; cout <<'}'<<" (L"<<LINE<<")"<<endl;}
using namespace std;
using ll = long long;
using ld = long double;
using vi = vector<int>;
using vivi = vector<vi>;
using vll = vector<long long>;
using vllvll = vector<vll>;
using vs = vector<string>;
using um = unordered_map<long long, long long>;
const long long INF = 1LL << 60;
const long long MOD = 1e9 + 7;
const long long MAX = 1000;

ll n;
vllvll M(MAX,vll(0));
vll ts1(MAX);
vll ts2(MAX);
vll seen(MAX, 0);

void rec(ll node, ll& ptr)
{
    ts1[node] = ptr++;
    seen[node] = 1;
    for (ll adj : M[node]) {
        if (seen[adj] == 1) continue;
        rec(adj, ptr);
    }
    ts2[node] = ptr++;
}

void dfs()
{
    ll ptr = 1;
    rep(i, 0, n) {
        if (seen[i] == 0) {
            rec(i, ptr);
        }
    }
}

int main()
{
    cin >> n;
    ll u, k, v;
    rep(i, 0, n) {
        cin >> u >> k;
        --u;
        rep(j, 0, k) {
            cin >> v;
            --v;
            M[u].push_back(v);
        }
    }
    ll f = 0, l = 0;
    dfs();
    rep(i, 0, n) {
        cout << i+1 << ' ' << ts1[i] << ' ' << ts2[i]<< endl;
    }
}

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

map<int, vector<int>> A;
int color[101];
int start[101];
int endTime[101];
int elapsed = 0;

void dfs(int u) {
    elapsed++;
    color[u] = 1;
    start[u] = elapsed;
    for (vector<int>::iterator it = A[u].begin(); it != A[u].end(); it++) {
        if (color[*it] == 0) {
            dfs(*it);
        }
    }
    endTime[u] = ++elapsed;
}

int main() {
    int n;
    cin >> n;

    int u, k;
    for (int i = 1; i <= n; i++) {
        color[i] = 0;
        cin >> u >> k;
        int ad;
        for (int j = 0; j < k; j++) {
            cin >> ad;
            A[u].push_back(ad);
        }
    }

    for (int i = 1; i <= n; i++) {
        if (color[i] == 0) dfs(i);
    }

    for (int i = 1; i <= n; i++) {
        cout << i << " " << start[i] << " " << endTime[i] << endl;
    }
}