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>
using namespace std;
int t=1, n, M[100][100], color[100], d[100], f[100];
void dfs(int u){
	color[u]=1;
	d[u]=t;
	t++;
	for(int v=0; v<n; v++){
		if(M[u][v]==1 && color[v]==0){
			dfs(v);
		}
	}
	color[u]=2;
	f[u]=t;
	t++;
}
int main(){
	cin>>n;
	for(int i=0; i<n; i++){
		color[i]=0;
		d[i]=0;
		f[i]=0;
		for(int j=0; j<n; j++){
			M[i][j]=0;

		}
	}
	for(int i=0; i<n; i++){
		int u, k, child;
		cin>>u>>k;
		for(int j=0; j<k; j++){
			cin>>child;
			M[u-1][child-1]=1;
		}
	}
	for(int i=0; i<n; i++){
		if(color[i]==0)
			dfs(i);
	}
	for(int i=0; i<n; i++)
		cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
	return 0;
}

C++: #include <iostream>
#include <fstream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <algorithm>
#include <complex>
#include <array>
#include <iomanip>
using namespace std;

#define REP(i,n) for(int i=0; i<n; ++i)
#define FOR(i,a,b) for(int i=a; i<=b; ++i)
#define FORR(i,a,b) for (int i=a; i>=b; --i)
#define ALL(c) (c).begin(), (c).end()

typedef long long ll;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef vector<long double> VD;
typedef vector<VI> VVI;
typedef vector<VL> VVL;
typedef vector<VD> VVD;
typedef pair<int,int> P;
typedef pair<ll,ll> PL;

template<typename T> void chmin(T &a, T b) { if (a > b) a = b; }
template<typename T> void chmax(T &a, T b) { if (a < b) a = b; }

int in() { int x; scanf("%d", &x); return x; }
ll lin() { ll x; scanf("%lld", &x); return x; }
#define INF 1LL<<60

int timestamp = 1;

void dfs(int from, vector< vector<int> >& edges, vector<int>& d, vector<int>& f) {
    if(d[from] > 0) return;
    d[from] = timestamp++;
    for(int next: edges[from]) {
        if(d[next] == 0)
            dfs(next, edges, d, f);
    }
    f[from] = timestamp++;
}

int main() {
    int N;
    cin >> N;
    vector<vector<int> > edges(N+1);
    REP(i, N) {
        int u, k;
        cin >> u >> k;
        edges[u].resize(k);
        REP(j, k) cin >> edges[u][j];
        sort(ALL(edges[u]));
    }

    vector<int> d(N+1), f(N+1);
    FOR(i, 1, N)
        dfs(i, edges, d, f);
    FOR(i, 1, N) {
        cout << i << " " << d[i] << " " << f[i] << endl;
    }
    return 0;
}

C++: #include <stdio.h>
#include <iostream>
#include <utility>
#include <algorithm>
#include <math.h>
#include <vector>
#include <list>

using namespace std;
int n;
list<int> adj[101];
int d[101] = {};
int f[101] = {};

void DFS(int v)
{
    static int num = 1;
    d[v] = num++;
    while (!adj[v].empty())
    {
        if (d[adj[v].front()] == 0)
            DFS(adj[v].front());
        adj[v].pop_front();
    }
    f[v] = num++;
}

void print()
{
    for (int i = 1; i <= n; i++)
    {
        printf("%d %d %d\n", i, d[i], f[i]);
    }
}

int main()
{
    int u, k, v;
    cin >> n;

    for (int i = 0; i < n; i++)
    {
        cin >> u >> k;
        while (k > 0)
        {
            cin >> v;
            adj[u].push_back(v);
            k--;
        }
    }

    DFS(1);

    print();

    return 0;
}

C++: /* 
 * ALDS1_11B.cpp
 */
#include <iostream>
#include <vector>
#include <cstdio>
#include <cstdlib>
#include <cstring>

using namespace std;

int N;
int ad_k[101];
int ad_list[101][101];

int jikan = 0;
int d[101], f[101];
bool visited[101];

void visit(int id) {
    if (visited[id])
        return;

    visited[id] = true;
    d[id] = ++jikan;
    for (int i = 0; i < ad_k[id]; ++i) {
        visit(ad_list[id][i]);
    }
    f[id] = ++jikan;
}

int main(void) {

    scanf("%d", &N);
    for (int i = 1, id; i <= N; ++i) {
        scanf("%d", &id);
        scanf("%d", ad_k + id);
        for (int j = 0; j < ad_k[id]; ++j) {
            scanf("%d", ad_list[id] + j);
        }
    }

    for (int i = 1; i <= N; ++i) {
        visit(i);
    }

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

    return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
#include<unordered_map>

using namespace std;
typedef pair<long long int, long long int> PP;

long long int INF = 1e18;
long long int MOD = 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 += 1;
  for(int to : E[pos]){
    time = func(to, time);
  }
  f[pos] = time;
  time += 1;
  return time;
}

int main(){
  int n;
  cin >> n;
  for(int loop = 0; loop < n; loop++){
    int u, k;
    cin >> u >> k;
    for(int i = 0; i < k; i++){
      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;
  }
  return 0;
}