Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

type vertexId int

type vertex struct {
	id vertexId
	firstVisitAt int
	finishVisitAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		firstVisitAt: 0,
		finishVisitAt: 0,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.firstVisitAt > 0
}

func dfs(currentId vertexId, timestamp int, vertices []vertex) int {
	currentVertex := &vertices[currentId-1]
	if currentVertex.isVisited() {
		return timestamp
	}
	timestamp = timestamp + 1
	currentVertex.firstVisitAt = timestamp
	for _, adjId := range currentVertex.adjs {
		timestamp = dfs(adjId, timestamp, vertices)
	}
	timestamp = timestamp + 1
	currentVertex.finishVisitAt = timestamp
	return timestamp
}

func solveDfs(vertices []vertex) {
	timestamp := 0
	for {
		vid := vertexId(-1)
		for i := 0; i < len(vertices); i++ {
			if !vertices[i].isVisited() {
				vid = vertexId(i+1)
				break
			}
		}
		if vid > 0 {
			timestamp = dfs(vid, timestamp, vertices)
		} else {
			break
		}
	}
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveDfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", vertices[i].id, vertices[i].firstVisitAt, vertices[i].finishVisitAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define repR(i, n) for(int i = (n) - 1; i > -1; i--)
#define rep1(i, n) for(int i = 1; i < (int)(n + 1); i++)
#define rep1R(i, n) for(int i = (n); i > 0; i--)
using namespace std;

const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;

int n;
int M[110][110] = {};
int color[110];
int elapse = 0;
int d[110];
int f[110];

void dfs(int u) {
  color[u] = GRAY;
  d[u] = ++elapse;
  rep(v, n) {
    if (M[u][v] && color[v] == WHITE) dfs(v);
  }
  color[u] = BLACK;
  f[u] = ++elapse;
}

void dfs_init() {
  rep(i, n) color[i] = WHITE;
  dfs(0);
}

int main() {
  cin >> n;
  rep(i, n) {
    int id, deg;
    cin >> id >> deg;
    --id;    // 0-indexedに直す
    rep(j, deg) {
      int v;
      cin >> v;
      --v;    // 0-indexedに直す
      ++M[id][v];
    }
  }
  dfs_init();
  rep(i, n) {
    cout << i + 1 << " " << d[i] << " " << f[i] << endl;
  }
  return 0;
}

C++: #include<iostream>
#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,a[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(a[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++)a[i][j] = 0;
    }
    for(int i = 0;i < n;i++){
        cin >> u >> k;
        u--;
        for(int j = 0;j < k;j++){
            cin >> v;
            v--;
            a[u][v] = 1;
        }
    }
    dfs();
    
    return 0;
}

C++: #define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define int long long
#define rep(i,n) for(int i=0;i<n;i++)
#define Rep(i,a,b) for(int i=a;i<b;i++)
#define REP(i,a,b) for(int i=a;i<=b;i++)
#define rev(i,n) for(int i=n-1;i>=0;i--)
#define vi vector<int>
#define pb push_back
#define pi pair<int,int>
#define vp vector<pair<int,int>>
#define mp make_pair
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
#define MEMSET(a) memset(a,0,sizeof(a))
#define inf (1ll<<60)

using namespace std;

const int mod=1e9+7;

void run();

void init() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout<<fixed<<setprecision(12);
}

signed main(){
    init();
    run();
    return 0;
}

int d[101],f[101],t;

void dfs(vector<vi> a,int v){
    if(d[v])return;
    d[v]=++t;
    rep(i,a[v].size()){
        dfs(a,a[v][i]);
    }
    f[v]=++t;
}

void run(){
    int n;
    cin>>n;
    vector<vi> a(n+1);
    REP(i,1,n){
        int u,k;
        cin>>u>>k;
        rep(j,k){
            int v;
            cin>>v;
            a[u].pb(v);
        }
        sort(all(a[u]));
    }
    REP(i,1,n){
        dfs(a,i);
    }
    REP(i,1,n){
        cout<<i<<" "<<d[i]<<" "<<f[i]<<endl;
    }
}