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<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<bitset>
#include<vector>
#include<deque>
#include<queue>
#include<map>
#include<set>
#include<stack>
#include<cmath>
#include<iomanip>
#include <functional>
using namespace std;
typedef long long ll;
const int mod = 1000000007;
const int INF = 1 << 28;
//cout << fixed << std::setprecision(9)
//memset(a, 0, sizeof(a));
//--------------------------

int n;
bool g[110][110];
int d[110];
int f[110];

void dfs1(int s)
{
	if (d[s] != -1) return;

	stack<int> stk;
	d[s] = 0;
	stk.push(s);
	int current = 0;
	while (!stk.empty()) {
		int u = stk.top();
		int flag = 0;
		for (int j = 1; j <= n; j++) {
			if (g[u][j] && d[j] == -1) {
				flag = 1;
				stk.push(j);
				d[j] = ++current;
				break;
			}
		}

		if (flag == 0) {
			f[u] = ++current;
			stk.pop();
		}

	}
}

void dfs()
{
	for (int i = 1; i <= n; i++)
		dfs1(i);

}

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;
			g[u][v] = true;
		}
	}

	for (int i = 1; i <= n; i++) {
		d[i] = -1;
		f[i] = -1;
	}

	dfs();

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

	return 0;
}

C++: #define _USE_MATH_DEFINES

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
#include <list>

long long int INF = 1e18;
using namespace std;

typedef pair<long long int, long long int> P;

long long int DP[1001][1001] = {};

int n;
int s[200], t[200];
bool visited[200] = {};

int dfs(int u, int d){
	if(visited[u]){
		return d - 1;
	}
	visited[u] = true;
	s[u] = d;
	for(int i = 0; i < n; i++){
		if(DP[u][i]){
			d = dfs(i, d + 1);
		}
	}
	t[u] = d + 1;
	return d + 1;
}

int main(){
	
	cin >> n;
	
	for(int loop = 0; loop < n; loop++){
		
		int id, k;
		cin >> id >> k;
		id--;
		
		for(int i = 0; i < k; i++){
			int num;
			cin >> num;
			num--;
			DP[id][num] = 1;
		}
		
	}
	
	dfs(0, 1);
	
	for(int i = 0; i < n; i++){
		cout << i + 1 << " " << s[i] << " " << t[i] << endl;
	}
	
	return 0;
}

C++: #include <iostream>
#include <vector>

using namespace std;

const int MAX = 100;

class DFS
{
    vector< vector<int> > adj;
    int num, d[MAX], f[MAX], parent[MAX], status[MAX], tt;

public:
    DFS()
    {
        cin >> num;
        for (int i = 0; i < num; i++)
        {
            d[i] = status[i] = 0;
            parent[i] = -1;
        }

        load(num);
        tt = 0;
    }

    void load(int n)
    {
        int r, c, n_c;
        adj.assign(n, vector<int>());
        for (int i = 0; i < n; i++)
        {
            cin >> r >> n_c;
            adj[r - 1].assign(n_c, int());
            for (int j = n_c - 1; j >= 0; j--)
            {
                cin >> c;
                adj[r - 1].at(j) = c-1;
            }
        }
    }

    int next(int node)
    {
        if (!adj[node].empty())
        {
            int v = adj[node].back();
            adj[node].pop_back();
            return v;
        }
        return -1;
    }

    void run(int node)
    {
        int next_node;
        while (node != -1)
        {
            if (status[node] == 0)
            {
                status[node] = 1;
                d[node] = ++tt;
            }
            next_node = next(node);
            if (next_node == -1)
            {
                status[node] = 2;
                f[node] = ++tt;
                node = parent[node];
                continue;
            }
            if (status[next_node] == 0)
            {
                parent[next_node] = node;
                node = next_node;
            }
        }
    }

    void dfs(){
        for(int node=0;node<num;node++){
            if(status[node] == 0) run(node);
        }
    }

    int dd(int n)
    {
        return d[n];
    }

    int ff(int n)
    {
        return f[n];
    }

    int number()
    {
        return num;
    }
};

int main()
{
    DFS dfs;

    dfs.dfs();
    for (int i = 0; i < dfs.number(); i++)
    {
        cout << i + 1 << " " << dfs.dd(i) << " " << dfs.ff(i) << endl;
    }
}

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

static const int N = 100;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n,M[N][N];
int color[N],d[N],f[N],tt;
int nt[N];

int next(int u){
  for(int v=nt[u];v<n;v++){
    nt[u] = v+1;
    if(M[u][v]) return v;
  }
  return -1;
}

void dfs_visit(int r){
  for(int i=0;i<n;i++) nt[i] = 0;

  stack<int> S;
  S.push(r);
  color[r] = GRAY;
  d[r] = ++tt;

  while(!S.empty()){
    int u = S.top();
    int v = next(u);
    if(v != -1){
      if(color[v] == WHITE){
        color[v] = GRAY;
        d[v] = ++tt;
        S.push(v);
      }
    }else{
      S.pop();
      color[u] = BLACK;
      f[u] = ++tt;
    }
  }
}

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

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

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

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

  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;
    }
  }

  dfs();
  return 0;
}