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 <cstring>
using namespace std;

const int Max = 105;
int G[Max][Max], color[Max], d[Max], f[Max];
int t, n;

void dfs_visit(int u)
{
    color[u] = 0;
    d[u] = ++t;
    for(int j=0; j<n; j++)
    {
        if(!G[u][j]) continue;
        if(color[j]==-1)
            dfs_visit(j);
    }
    color[u] = 1;
    f[u] = ++t;
}
void dfs()
{
    memset(color, -1, sizeof(color));
    t = 0;
    for(int i=0; i<n; i++)
    {
        if(color[i]==-1)
            dfs_visit(i);
    }
    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++)
    {
        cin >> u >> k;
        for(int j=0; j<k; j++)
        {
            cin >> v;
            G[u-1][v-1] = 1;
        }
    }
    dfs();
    return 0;
}

C++: #include<bits/stdc++.h>
//cout<<setprecision(1)<<fixed<<endl;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int MAX_N=100000;
const int INF = 0x3f3f3f3f;
#define eps 1e-7
//#define Kongxiangzhouye
int n;
int a[123][123];
int st[123];
int ed[123];
int now;
void dfs(int local){
	st[local]=now++;
	int flag=1;
	for(int i=1;i<=n;i++){
		if(a[local][i]==1){
			if(st[i]==0){
				flag=0;
				dfs(i);
			}
		}
	}
	ed[local]=now++;
}
int main(){
	ios::sync_with_stdio(false);
	#ifdef Kongxiangzhouye
		freopen("in.txt","r",stdin);
		freopen("out.txt","w",stdout);
	#endif
	while(cin>>n){
		memset(a,0,sizeof(a));
		memset(st,0,sizeof(st));
		memset(ed,0,sizeof(ed));
		for(int i=0;i<n;i++){
			int t,m;
			cin>>t>>m;
			for(int i=0;i<m;i++){
				int te;
				cin>>te;
				a[t][te]=1;
			}
			now=1;
		}
		dfs(1);
		for(int i=1;i<=n;i++){
			cout<<i<<" "<<st[i]<<" "<<ed[i]<<endl;
		}
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

int n;
int cnt1 = 0; 
vector<int> d(n);
vector<int> f(n);
void dfs(const Graph &G, int v){
    cnt1++;
    d[v - 1] = cnt1;
    for(auto nv : G[v - 1]){
        if(d[nv - 1] != 0) continue;
        dfs(G, nv);
    }
    cnt1++;
    f[v - 1] = cnt1;
}

int main(){
    cin >> n;
    Graph G(n); 
    for(int i = 0; i < n; i++){
        int a, b; cin >> a >> b;
        if(b == 0) continue;
        for(int j = 0; j < b; j++){
            int x; cin >> x;
            G[a - 1].push_back(x);
        }
    }
    d.assign(n, 0);
    f.assign(n, 0);
    for(int i = 1; i <= n; i++){
      if(d[i - 1] == 0) dfs(G, i);
    }
    for(int i = 1; i <= n; i++){
        cout << i << " " << d[i - 1] << " " << f[i - 1] << endl; 
    }
}

C++: #include <iostream>
#define MAX 101

using namespace std;

bool flag[MAX][MAX];
int t[MAX][2];
int n;

void dfs(int num){
	static int cnt = 1;
	
	if(t[num][0] == 0)t[num][0] = cnt++;
	else return;
	for(int i=1;i<=n;++i){
		if(flag[num][i] == true){
			dfs(i);
		}
	}
	t[num][1] = cnt++;
}

int main(){
	int u, k, v, i, j; 
	
	cin >> n;
	for(i=1;i<=n;++i){
		cin >> u >> k;
		for(j=0;j<k;++j){
			cin >> v;
			flag[u][v] = true;
		}
		 
	}
	for(int i=1;i<=n;++i)dfs(i);
	for(int i=1;i<=n;++i)cout << i << " " << t[i][0] << " " << t[i][1] << endl;
	
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr ll MOD = 1000000007;
constexpr ll INF = 1ll<<60;

using Graph = vector<vector<ll>>;
Graph G;
ll d[110], f[110];

void DFS(ll v, ll &t)
{
	if (d[v] != -1) return;
	d[v] = t;

	++t;
	for (auto &nv : G[v])
	{
		DFS(nv, t);
	}
	f[v] = t;
	++t;
}

int main(int argc, char **argv)
{
	ll N; cin >> N;
	G.resize(N);
	for (ll i = 0; i < N; ++i)
	{
		ll n, k; cin >> n >> k;
		--n;
		for (ll j = 0; j < k; ++j)
		{
			ll v; cin >> v;
			--v;
			G[n].push_back(v);
		}
		sort(G[n].begin(), G[n].end());
	}
	fill(d, d+110, -1);
	fill(f, f+110, -1);

	ll t = 1;
	for (ll v = 0; v < N; ++v)
	{
		if (d[v] == -1)
			DFS(v, t);
	}

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