Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const N = 100

const (
	WHITE = iota
	GRAY
	BLACK
)

type Graph struct {
	M               [N][N]int
	color, d, f, nt [N]int
	tt              int
}

func (g *Graph) next(u, n int) int {
	for v := g.nt[u]; v < n; v++ {
		g.nt[u] = v + 1
		if g.M[u][v] != 0 {
			return v
		}
	}
	return -1
}

func (g *Graph) dfsVisit(r, n int) {
	var S []int
	S = append([]int{r}, S...)
	g.color[r] = GRAY
	g.tt++
	g.d[r] = g.tt

	for len(S) != 0 {
		u := S[0]
		v := g.next(u, n)
		if v == -1 {
			S = S[1:]
			g.color[u] = BLACK
			g.tt++
			g.f[u] = g.tt
			continue
		}

		if g.color[v] != WHITE {
			continue
		}

		g.color[v] = GRAY
		g.tt++
		g.d[v] = g.tt
		S = append([]int{v}, S...)
	}
}

func (g *Graph) dfs(n int) string {
	for i := 0; i < n; i++ {
		g.color[i] = WHITE
	}
	g.tt = 0

	for u := 0; u < n; u++ {
		if g.color[u] == WHITE {
			g.dfsVisit(u, n)
		}
	}

	var out bytes.Buffer
	for i := 0; i < n; i++ {
		out.WriteString(fmt.Sprintf("%d %d %d\n", i+1, g.d[i], g.f[i]))
	}

	return strings.TrimRight(out.String(), "\n")
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	var g Graph
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		u--
		for j := 0; j < k; j++ {
			sc.Scan()
			v, _ := strconv.Atoi(sc.Text())
			v--
			g.M[u][v] = 1
		}
	}

	return g.dfs(n)
}

func main() {
	fmt.Println(answer(os.Stdin))
}

C++: #include<stdio.h>
#define N 100
#define WHITE 0
#define GRAY 1 
#define BLACK 2
 
int n, M[N][N];
int color[N], d[N], f[N], tt; 

void dfs_visit(int u) {
	int v;
	color[u] = GRAY;
	d[u] = ++tt;
	for(v = 0; v < n; v++) {
		if(M[u][v] == 0) continue;
		if(color[v] == WHITE) {
			dfs_visit(v);
		}
	}
	color[u] = BLACK;
	f[u] = ++tt;
}

void dfs() {
	int u;
	for(u = 0; u < n; u++) color[u] = WHITE;
	tt = 0;
	
	for(u = 0; u < n; u++) {
		if(color[u] == WHITE) dfs_visit(u);
	}
	
	for(u = 0; u < n; u++) {
		printf("%d %d %d\n", u + 1, d[u], f[u]);
	}
}
 
int main() {
    int u, k, v, i j;
    
    scanf("%d", 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++) {
        scanf("%d %d", &u, &k);
        u--;
        for(int j = 0; j < k; j++ ) {
           scanf("%d", &v);
           v--;
           M[u][v] = 1; 
        }       
    }
     
     
    dfs();
     
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;

#define rep(i, n) for (int i = 0; i < n; ++i)
#pragma region Debug
template <typename T>
void view(const std::vector<T> &v)
{
    for (const auto &e : v)
    {
        std::cout << e << " ";
    }
    std::cout << std::endl;
}
template <typename T>
void view(const std::vector<std::vector<T>> &vv)
{
    for (const auto &v : vv)
    {
        view(v);
    }
}
#pragma endregion

vector<vector<int>> g;
vector<int> d, f;

int dfs(int v, int t)
{
    // cout << v << " ";
    if (f[v] != INT32_MAX)
    {
        return f[v];
    }
    if (d[v] != INT32_MAX && f[v] == INT32_MAX)
    {
        return t - 1;
    }

    d[v] = min(d[v], t);

    int tt = t + 1;
    for (auto to : g[v])
    {
        if (v == to)
            continue;
        tt = max(tt, dfs(to, tt) + 1);
    }
    f[v] = min(tt, f[v]);

    return tt;
}

int main()
{
    int n;
    cin >> n;
    g = vector<vector<int>>(n, vector<int>());
    d = vector<int>(n, INT32_MAX);
    f = vector<int>(n, INT32_MAX);

    rep(i, n)
    {
        int k;
        cin >> k >> k;
        rep(j, k)
        {
            int t;
            cin >> t;
            t--;
            g[i].emplace_back(t);
        }
    }

    int t = 1;
    rep(i, n)
    {
        if (f[i] == INT32_MAX)
        {
            t = dfs(i, t) + 1;
        }
    }

    rep(i, n)
    {
        cout << (i + 1) << " " << d[i] << " " << f[i] << endl;
    }

    return 0;
}

C++: #include<stdio.h>

int d[100],f[100],n,g[100][100],time=1;

int func(int m){
    d[m]=time++;
    int i,j;
    for(i=0;i<n;i++){
        if(g[m][i]==1 && d[i]==0){
            func(i);
        }
    }
    f[m]=time++;
}

int main(void){
    int i, j, u, k, v;
    scanf("%d",&n);
    for(i=0;i<n;i++){
        scanf("%d %d",&u,&k);
        for(j=0;j<k;j++){
            scanf("%d",&v);
            g[u-1][v-1]=1;
        }
    }
    func(0);
    for(i=0;i<n;i++){
        if(d[i]==0){
            func(i);
        }
    }
    for(i=0;i<n;i++){
        printf("%d %d %d\n",i+1,d[i],f[i]);
    }
    return 0;
}

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

using namespace std;

int g[101][101];
int d[101], f[101];
int t = 0, n;

int dfs(int x){
    t++;
    for(int i=1; i<=n; i++){
        if(d[x] == 0) d[x] = t;
       
        if(g[x][i] == 1 && f[i] == 0){
            dfs(i);
            t++;   
        }
        
        if(i==n && f[x] == 0){
            f[x] = t+1;
        }
    }
    return 0;        
  
}

int main(){
    cin >> n;

    for(int i=1; i<=n; i++){
        for(int j=1; j<=n; j++){
            g[i][j] = 0;
        }
        d[i] = 0;
        f[i] = 0;
    }
    
    int u,k;
    for(int i=0; i<n; i++){
        cin>>u>>k;
        for(int j=0; j<k; j++){
            int v;
            cin>>v;
            g[u][v] = 1;
        }
    }

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

C++: #include <iostream>
#include<string>
#include<cmath>
#include<algorithm>
#include<cctype>
#include<queue>
#include<stack>
#include<stdio.h>
#include<vector>
#include<set>
#include<map>
#include<array>
#include<iomanip>
#define rep(i,n) for(int i=0;i<n;i++)
typedef int long long ll;

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];//グラフの隣接行列
int color[N],d[N],f[N],tt;//状態
int nt[N];

int next(int u){
    
    for(int v=nt[u];v<n;v++){
        nt[u]=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){
            cout<<"a"<<endl;
            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;
}