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<cstdio>
#include<array>
#include<vector>
#include<stack>
using namespace std;
const int MAX_V=101;
array<int,MAX_V> open{0};
array<int,MAX_V> close{0};
array<vector<int>,MAX_V> edge;
int t=0;

void dfs(int f){
  open[f]=++t;
  for(int a:edge[f]){
    if(open[a]==0){
      dfs(a);
    }
  }
  close[f]=++t;
}

int main(){
  int n;scanf("%d",&n);
  for(int i=0;i<n;i++){
    int u;scanf("%d",&u);
    int k;scanf("%d",&k);
    for(int j=0;j<k;j++){
      int v;scanf("%d",&v);
      edge[u].push_back(v);
    }
  }
  for(int i=0;i<n;i++)
    if(open[i+1]==0)
      dfs(i+1);
  for(int i=0;i<n;i++){
    printf("%d %d %d\n",i+1,open[i+1],close[i+1]);
  }
}

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

int A[101][101] = {0};
int n, tt = 0, d[101] = {0}, f[101] = {0}, color[101] = {0};
stack<int> S;

int next(int u) {
    int i;
    for ( i = 1; i <= n; i++ ) {
        if ( A[u][i] == 1 && color[i] != 1 ) return i;
    }

    return -1;
}

void dfs (int u) {
    int i, j ,k;
    S.push(u);
    d[u] = ++tt;
    color[u] = 1;
    while ( !S.empty() ) {
        j = S.top();
        i = next(j);
        if ( i != -1 ) {
            color[i] = 1;
            d[i] = ++tt;
            S.push( i );
        }
    else {
        f[j] = ++tt;
        S.pop();
    }
    }

}

int main() {
    int i, j, k, v;
    cin >> n;
    for ( i = 0; i < n; i++ ) {
        cin >> j >> k;
        while ( k-- ) {
            cin >> v;
            A[j][v] = 1;
        }
    }

    for ( i = 1; i <=n; i++ ) if ( color[i] != 1 ) dfs(i);
    for ( i = 1; i <=n; i++ ) cout << i << ' ' << d[i] << ' ' << f[i] << endl;

    return 0;

}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cassert>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define rep(i,n) FOR(i,0,n)
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define vint vector<int>
#define vdouble vector<double>
#define vstring vector<string>
using namespace std;

#include<map>
#include<set>
#include<queue>

typedef long long ll;
typedef unsigned long long ull;

const int MAX_N = 1000000;
static const int INFTY = (1 << 21);

class Edge{
public:
    int from, to, cost;
    Edge(int from = 0, int to = 0, int cost = 0) :
            from(from), to(to), cost(cost){}

    bool operator < (const Edge &e) const{
        return cost < e.cost;
    }
    bool operator >(const Edge &e) const{
        return cost > e.cost;
    }

};

class Node{
public:
    vector<Edge> edges;
    int dist;
    int done;
    int times;
    int timee;

    Node(){
        dist = INFTY;
        done = 0;
    }
};

class Graph{
public:
    vector<Node> nodes;
    Graph(int n) {
        rep(i, n) { Node n;  nodes.push_back(n); }
    }
    Node& operator[](int i){
        return nodes[i];
    }
};

class Data{

public:
    int dist;
    Edge *edge;
    Data(int dist, Edge *edge) {
        this->dist = dist;
        this->edge = edge;
    }

    bool operator < (const Data &d) const{
        return dist < d.dist;
    }
    bool operator >(const Data &d) const{
        return dist > d.dist;
    }
};

Graph G(0);

int V;
int t;

void dfs(int v){
    if (G[v].done != 0) return;

    // fprintf(stderr, "%d %d\n", v, t);

    G[v].done = 1;
    t++;
    G[v].times = t;
    for(auto &e: G[v].edges){
        dfs(e.to);
    }
    t++;
    G[v].timee = t;
}

void dfs_run(){
    t = 0;
    dfs(0);
}

int main() {

    int V;
    cin >> V;
    G = Graph(V);

    rep(i, V){
        int from; cin >> from; from--;
        int e_count; cin >> e_count;

        vint vec;
        rep(j, e_count){
            int to; cin >> to; to--;
            vec.push_back(to);
        }
        sort(vec.begin(), vec.end());
        rep(j, e_count){
            G[from].edges.push_back(Edge(from, vec[j], 1));
        }
    }

    dfs_run();

    rep(i, V){
        fprintf(stdout, "%d %d %d\n", i+1, G[i].times, G[i].timee);
    }
}