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 <map>
#include <set>
#include <list>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <utility>
#include <iostream>
#include <algorithm>
#include <functional>
#include <unordered_map>
#include <unordered_set>

using namespace std;

#define ll long long
#define ull unsigned long long
#define INF (1 << 30)
#define LLINF (1LL << 62)
#define MOD7 1000000007
#define MOD9 1000000009
#define eps 1e-9
#define P pair<int, int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pul pair<ull, ull>
#define all(a) (a).begin(), (a).end()
#define FOR(i,a,b) for (int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);--i)
#define REP(i,n) for (int i=0;i<(n);++i)
#define RREP(i,n) for (int i=(n)-1;i>=0;--i)

void YES() { cout << "YES" << endl; }
void NO() { cout << "NO" << endl; }
void Yes() { cout << "Yes" << endl; }
void No() { cout << "No" << endl; }
void yes() { cout << "yes" << endl; }
void no() { cout << "no" << endl; }

template<class T>
class DirectedGraph {
public:
	class Edge {
	public:
		int to;
		T cost;

		Edge(int t, T c) : to(t), cost(c) {}

		bool operator<(const Edge& right) const {
			return cost == right.cost ? to < right.to : cost < right.cost;
		}
	};

	vector<vector<Edge>> G;
	int V;

	DirectedGraph(int n = 0) {
		resize(n);
	}

	void resize(int n) {
		V = n;
		G.resize(n);
	}

	void addEdge(int from, int to, T cost = 0) {
		int v = max(from, to);
		if (v >= V)
			resize(v + 1);
		G[from].push_back(Edge(to, cost));
	}


	int t = 1;
	vector<pii> stamp;
	vector<bool> visit;
	void dfs(int s) {
		visit.resize(V);
		stamp.resize(V);
		calcDfs(s);
	}

	void calcDfs(int s) {
		if (visit[s])
			return;

		stamp[s].first = t++;

		visit[s] = true;
		for (int i = 0; i < G[s].size(); ++i) {
			calcDfs(G[s][i].to);
		}

		stamp[s].second = t++;
	}

	vector<int> bfs() {

	}
};

int main() {
	DirectedGraph<int> g;
	int n, id, k, to;
	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> id >> k;
		while (k--) {
			cin >> to;
			g.addEdge(id, to);
		}
	}

	for (int i = 1; i <= n; ++i)
		g.dfs(i);

	for (int i = 1; i <= n; ++i) {
		printf("%d %d %d\n", i, g.stamp[i].first, g.stamp[i].second);
	}

	return 0;
}

C++: #include<iostream>
#include<vector>
using namespace std;
int cnt=1;
void depth(vector< vector<int> > &vv,vector<int> &f,vector<int> &c,int num){
	
	f[num]=cnt;
	cnt++;
	
	for(int i=0; i<vv[num].size(); i++){
		if(vv[num][i]!=0 && f[i]==0){
			depth(vv,f,c,i);
		}
	}

	c[num]=cnt;
	cnt++;

}
int main(){
	int n;
	cin>>n;
	vector< vector<int> > v(n,vector<int> (n,0));
	vector<int> ft(n,0);
	vector<int> ct(n,0);
	int u[n];
	for(int i=0; i<n; i++){
		int k;
		cin>>u[i]>>k;
		for(int j=0; j<k; j++){
			int x;
			cin>>x;
			v[i][x-1]=1;
		}
	}
	for(int i=0; i<n; i++){
		if(ft[i]==0){
			depth(v,ft,ct,i);
		}
		cout<<u[i]<<" "<<ft[i]<<" "<<ct[i]<<endl;
	}
  return 0;
}