Go: package main

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

type TimeRecord struct {
	discoverTime int
	finishTime   int
}

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

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

	timeRecordMap := make([]TimeRecord, n)
	childrenMap := make([][]int, n)
	for i := 1; i <= n; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		timeRecordMap[node-1] = TimeRecord{-1, -1}

		childNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		childrenMap[node-1] = make([]int, childNum)
		for j := 0; j < childNum; j++ {
			child, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			childrenMap[node-1][j] = child
		}
	}

	// TODO: always start with 1?
	timer := 1
	visit(1, &timer, childrenMap, timeRecordMap)
	for k, v := range timeRecordMap {
		fmt.Printf("%d %d %d\n", k+1, v.discoverTime, v.finishTime)
	}
}

func visit(currentNode int, timer *int, childrenMap [][]int, timeRecordMap []TimeRecord) {
	if timeRecordMap[currentNode-1].discoverTime > 0 {
		return
	}
	children := childrenMap[currentNode-1]
	timeRecordMap[currentNode-1] = TimeRecord{*timer, timeRecordMap[currentNode-1].finishTime}
	(*timer)++
	for i := 0; i < len(children); i++ {
		visit(children[i], timer, childrenMap, timeRecordMap)
	}
	timeRecordMap[currentNode-1] = TimeRecord{timeRecordMap[currentNode-1].discoverTime, *timer}
	(*timer)++
}

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

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, M[N][N];
int color[N], d[N], f[N], tt;
int nt[N];

// u に隣接する v を番号順に取得
int next(int u) {
  for ( int v = nt[u]; v < n; v++ ) {
    nt[u] = v + 1;
    if ( M[u][v] ) return v;
  }
  return -1;
}

// スタックを用いた深さ優先探索
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() {
  // 初期化
  for ( int i = 0; i < n; i++ ) {
    color[i] = WHITE;
    nt[i] = 0;
  }
  tt = 0;

  // 未訪問の u を始点として深さ優先探索
  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++ ) 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;
}

C++: #include <iostream>
#include <string>
#include <stdio.h>
using namespace std;

int d[100];
int f[100];
int map[100][100];
int time=0;
int n;
void visit(int);

int main(){
	int i,j,k,u,v;
	for(i=0;i<100;i++) d[i]=-1;
	for(i=0;i<100;i++) f[i]=-1;
	cin >> n;
	for(i=0;i<n;i++){
		for(j=0;j<n;j++){
			map[i][j]=0;
		}
	}
	for(i=0;i<n;i++){
		cin>>u>>k;
		for(j=0;j<k;j++){
			cin>>v;
			map[u-1][v-1]=1;
		}
	}
	visit(0);
	// ??¨???????????????????????????????????°?¨????????????¨??????
	for(i=0;i<n;i++){
		cout<< i+1 << " "<<d[i]<< " "<<f[i];
		cout<<endl;
	}
	return 0;
}

void visit(int k){
	int i;
	d[k]=++time;
	for(i=0;i<n && f[k]==-1;i++){
		if(map[k][i]==1&&d[i]==-1){
			visit(i);
		}
	}
	f[k]=++time;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep1(i, n) for (int i = 1; i < (n); ++i)
using namespace std;
typedef long long ll;

vector<vector<int>> g;
vector<bool> seen;
vector<int> found;

void dfs(int v){
    seen[v] = true;
    found.push_back(v);

    if(g[v].size()==0){
        return;
    }

    for(int nv: g[v]){
        if(!seen[nv]){
            dfs(nv);
            found.push_back(nv);
        }
    }
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    g.resize(n);
    seen.resize(n, false);

    rep(i, n){
        int u, k;
        cin >> u >> k;
        --u;
        rep(j, k){
            int v;
            cin >> v;
            --v;

            g[u].push_back(v);
        }
    }

    rep(i, n){
        if(!seen[i]) {
            dfs(i);
            found.push_back(i);
        }
    }
    
    vector<vector<int>> res(n, vector<int>(2, -1));
    rep(i, n){
        rep(j, found.size()){
            if(found[j]==i && res[i][0]==-1) res[i][0] = j+1;
            if(found[j]==i && res[i][0]!=-1) res[i][1] = j+1;
        }
    }

    rep(i, n) cout << i+1 << " " << res[i][0] << " " << res[i][1] << 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,M[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(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) 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;
}

C++: //


#include <iostream>
#include <stack>
#include <vector>

using namespace std;

int n;
int G[105][105];
vector<int> d(105,0),f(105,0);
int t=0;

void dfs(int x){
    bool p = false;
    if(d[x]!=0) p = true;
    if(d[x]==0){
        t++;
        d[x]=t;
    }
    for (int j=1; j<=n; j++) {
        if (G[x-1][j-1]==1 and d[j]==0) {
            dfs(j);
        }
    }
    t++;
    if(p) t--;
    if(f[x]==0) f[x]=t;
}


int main(){
    cin >> n;
    for (int i =0; i<n; i++) {
        for (int j =0; j<n; j++) {
            G[i][j] = 0;
        }
    }
    for (int i=0;i<n;i++) {
        int p,m;
        cin >>p >> m;
        for (int j=0; j<m; j++) {
            int q;
            cin >> q;
            G[p-1][q-1]=1;
        }
    }
    for(int i=0;i<n;i++) {
        dfs(i+1);
    }
    for (int i=0; i<n; i++) {
        cout << i+1 << " "<<d[i+1]<<" "<<f[i+1]<<endl;
    }
}

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

void dfs(int n, int &t, vector< vector<int> >& g, vector<int>& d, vector<int>& f, vector<bool>& seen)
{
    t++;
    if (d[n] == 0) d[n] = t;
    seen[n] = true;
    for (int i = 0; i < g[n].size(); i++)
    {
        if (seen[g[n][i]]) continue;
        dfs(g[n][i], t, g, d, f, seen);
    }
    t++;
    f[n] = t;
}

int main()
{
    int n; cin >> n;
    vector< vector<int> > g(n, vector<int>());
    for (int i = 0; i < n; i++)
    {
        int u, k; cin >> u >> k; u--;
        for (int j = 0; j < k; j++)
        {
            int v; cin >> v; v--;
            g[u].push_back(v);
        }
    } 
    vector<int> d(n, 0);
    vector<int> f(n, 0);
    vector<bool> seen(n, false);
    int t = 0;
    for (int i = 0; i < n; i++)
        if (seen[i] == false)
            dfs(i, t, g, d, f, seen);
    for (int i = 0; i < n; i++)
    {
        cout << i + 1 << " " <<  d[i] << " " << f[i] << endl;
    }
}