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<string>
#include<stack>
#include<unordered_set>
#include<algorithm>

#define N 1000

int n, u, k, v;
int G[N][N];
std::stack<int> S;
std::unordered_set<int> hasVisited;
int count, d[N], f[N];

void visit(int x) {
    hasVisited.insert(x);
    d[x] = count++;
    for(int i = 1; i <= n; i++) {
        if(G[x][i] != 0 && hasVisited.find(i) == hasVisited.end()) {
            visit(i);
        }
    }
    f[x] = count++;
}

int main() {

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

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

    for(int i = 1; i <= n; i++) {
        if(hasVisited.find(i) == hasVisited.end())
            visit(i);
    }
    for(int i = 1; i <= n; i++) {
        printf("%i %i %i\n", i, d[i], f[i]);
    }

    return 0;
}

C++: //
// Created by tattsun on 2017/02/13.
//

#include <iostream>
#include <vector>

using namespace std;

#define VERTEX_MAX_NUM 101
#define NIL -1

int now = 0;
int n;
int start[VERTEX_MAX_NUM];
int finish[VERTEX_MAX_NUM];
bool visited[VERTEX_MAX_NUM];
vector<int> vertexes[VERTEX_MAX_NUM];

void _dfs(int node) {
    start[node] = ++now;
    visited[node] = true;

    auto& v = vertexes[node];

    for(auto it = v.begin(); it != v.end(); it++) {
        if(visited[*it])
            continue;
        _dfs(*it);
    }

    finish[node] = ++now;
}

void dfs() {
    for(int i=1; i<=n; i++) {
        if(visited[i]) continue;
        _dfs(i);
    }
}

int main() {
    for(int i=0; i<VERTEX_MAX_NUM; i++) {
        start[i] = NIL;
        finish[i] = NIL;
        visited[i] = false;
    }

    cin >> n;

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

    dfs();

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

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

int d[128];
int f[128];
bool c[128][128];
int n;
int t;
int checked[128];

void dfs(int i) {
  if( checked[i] ) return;
  checked[i] = true;
  t += 1;
  d[i] = t;
  for(int k = 1; k <= n; ++k) {
    if( c[i][k] ) {
      dfs(k);
    }
  }
  t += 1;
  f[i] = t;
  return;
}

int main(void) {

  for(int i = 0; i < 128; ++i) {
    for(int j = 0; j < 128; ++j) {
      c[i][j] = false;
    }
  }

  std::cin >> n;

  int u, k, v;
  for(int i = 0; i < n; ++i) {
    std::cin >> u >> k;
    for(int j = 0; j < k; ++j) {
      std::cin >> v;
      c[u][v] = true;
    }
  }

  dfs(1);

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

C++: #include<iostream>
#include<vector>
#include<stack>
using namespace std;
#define MAX 101
#define VISITED 0;
#define UNVISITED -1
#define NO_POSSIBLE_VERTICE -3


int d[MAX], f[MAX];
int timeStamp = 0;
vector<int> adj[MAX];
stack<int> S;

bool isAdjacentVerticeUnvisited(int currVertice, int i){
	if (f[adj[currVertice][i]] == UNVISITED) 
		return true;
	else
		return false;
}

int getNextPossibleVertice(int currVertice) {
	int i = 0;
		
	for (i = 0; i < adj[currVertice].size(); i++){
		if (isAdjacentVerticeUnvisited(currVertice, i)){
			return adj[currVertice][i];
		}
	}

	return NO_POSSIBLE_VERTICE;

}

void dfs() {

	while (!S.empty()) {
		int currVertice = S.top();

		int nextNode = getNextPossibleVertice(currVertice);

		// cout << "dfs " << currVertice << " nt:" << nextNode << "\n";

		if (nextNode == NO_POSSIBLE_VERTICE) {
			f[currVertice] = ++timeStamp;
			S.pop();
		} else {
			d[nextNode] = ++timeStamp;
			f[nextNode] = VISITED;
			S.push(nextNode);
		}
	}

}


int main() {
	int n, i, j, vertice, id, degree;
	cin >> n;

	for (i = 0; i < n; i++) {
		cin >> id;
		cin >> degree;
		for (j = 0; j < degree; j++) {
			cin >> vertice;
			if (id != vertice){
				adj[id].push_back(vertice);
			}
		}
	}
	// init
	for (i = 1; i <= n; i++) {
		f[i] = UNVISITED;
	}

	for (i = 1; i <= n; i++) {
		if (f[i] == UNVISITED) {
			S.push(i);
			d[i] = ++timeStamp;
			f[i] = VISITED;
			dfs();
		}
	} 
	

	// for (i = 1; i <= n; i++) {
	// 	for (j = 0; j < adj[i].size(); j++)
	// 		cout << " " << adj[i][j];
	// 	cout << "\n" << i <<" size : " << adj[i].size() << "\n";
	// }

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

}