Go: package main

import "fmt"

type node struct {
	id, d, v int
	adj      []node
}

var n int
var seen []bool
var graph []node

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func dfs(v, t int) int {
	// fmt.Printf("dfs(v %d, t %d) en:\n", v, t)
	seen[v] = true
	graph[v].v = t
	tt := t
	for _, vv := range graph[v].adj {
		if !seen[vv.id] {
			tt = max(tt, dfs(vv.id, tt+1))
		}
	}
	graph[v].d = tt + 1
	// fmt.Printf("dfs(v %d, t %d) ex: d %d\n", v, t, graph[v].d)
	return graph[v].d
}

func main() {
	fmt.Scan(&n)
	graph = make([]node, n+1)
	for i := 1; i <= n; i++ {
		var u, k, v int
		fmt.Scan(&u, &k)
		graph[u].id = u
		// 頂点uはk個の隣接頂点を持っている
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			var t node
			t.id = v
			graph[u].adj = append(graph[u].adj, t)
		}
	}
	// fmt.Println("n", n, "graph", graph)
	seen = make([]bool, n+1)
	// t := dfs(1, 1)
	v, t := 1, 1
	done := false
	for !done {
		tt := dfs(v, t)
		done = true
		for i := range seen {
			if !seen[i] {
				done = false
				v = graph[i].id
				t = tt
				break
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, graph[i].v, graph[i].d)
	}
}

C++: //
//  main.cpp
//  619
//
//  Created by 8595198919 on 14/06/16.
//  Copyright (c) 2014年 8595198919. All rights reserved.
//

#define _2
#ifdef _1
#include <iostream>
#include <cstdio>
#include <queue>
#define rep(i,n) for(int i = 0;i<n;i++)
using namespace std;

int dist[105];
queue<int> que;
vector<int> G[105];
int main(int argc, const char * argv[])
{
    int n;
    cin >> n;
    for(int i = 0;i <= n;i++) {
        dist[i]=-1;
    }
    for(int i = 0;i < n;i++){
        int u,k;
        int to;
        scanf("%d %d",&u,&k);
        for(int j=0;j<k;j++){
            scanf("%d",&to);
            G[u].push_back(to);
        }
    }
    que.push(1);
    dist[1]=0;
    while(!que.empty()){
        int now = que.front();
        que.pop();
        int d = dist[now];
        rep(i,G[now].size()){
            if(dist[G[now][i]]==-1){
                dist[G[now][i]]=d+1;
                que.push(G[now][i]);
            }
        }
    }
    for(int i = 1;i <= n;i++) {
        cout <<i <<" " << dist[i]<<endl;
    }
}
#endif

#ifdef _2

#include <iostream>
#include <cstdio>
#include <queue>
#define rep(i,n) for(int i = 0;i<n;i++)
using namespace std;


vector<int> G[105];
int d[105];
int f[105];
int tm = 1;
void dfs(int p){
    d[p]=tm;
    rep(i,G[p].size()){
        if(d[G[p][i]]==-1){
            tm++;
            dfs(G[p][i]);
        }
    }
    f[p] = ++tm;
    return;
}
int main(int argc, const char * argv[])
{
    int n;
    cin >> n;
    for(int i = 0;i <= n;i++) {
        d[i]=-1;
        f[i]=-1;
    }
    for(int i = 0;i < n;i++){
        int u,k;
        int to;
        scanf("%d %d",&u,&k);
        for(int j=0;j<k;j++){
            scanf("%d",&to);
            G[u].push_back(to);
        }
    }
    dfs(1);
    for(int i = 1;i <= n;i++){
        printf("%d %d %d\n",i,d[i],f[i]);
    }
}

#endif

C++: #include "bits/stdc++.h"
#include <unordered_set>

#define _CRT_SECURE_NO_WARNINGS

#define REP(i, n) for(decltype(n) i = 0; i < (n); i++)
#define REP2(i, x, n) for(decltype(x) i = (x); i < (n); i++)
#define REP3(i, x, n) for(decltype(x) i = (x); i <= (n); i++)
#define RREP(i, n) for (decltype(n) i = (n) - 1; i >= 0; i--)

#define ALL(a) (a).begin(),(a).end()
#define SORT(c) sort((c).begin(),(c).end())
#define DESCSORT(c) sort(c.begin(), c.end(), greater<int>())

using namespace std;

const int INF = 1000000000;
const double PI = 3.1415926535897932384626433832795;

// N, E, S, W
const int dx[4] = { -1, 0,  1,  0 };
const int dy[4] = { 0, 1,  0, -1 };

using LL = long long int;
using LD = long double;
using pii = pair<int, int>;
using pdd = pair<double, double>;
using pll = pair<LL, LL>;
using vi = vector<int>;
using vd = vector<double>;
using vs = vector<string>;
using vvi = vector<vi>;
using vll = vector<LL>;

//==============================================
int n, tt = 0;
vvi M;
vi D, F, searchStatus;

// ??±???????????¢?´¢
void antDfs(int u) {
	searchStatus[u] = 1;

	// ?????????(??????)??????????????????
	D[u] = ++tt;
	REP3(i, 1, n) {
		if (M[u][i] == 0) continue;

		if (searchStatus[i] == -1) {
			antDfs(i);
		}
	}
	// ?????????(??????)???????????????
	F[u] = ++tt;

	// ??¢?´¢??????
	searchStatus[u] = 1;
}

void print() {
	REP3(i, 1, n) {
		cout << i << " " << D[i] << " " << F[i] << "\n";
	}
}

void solve() {

	REP3(i, 1, n) {
		if (searchStatus[i] == -1) {
			//????¨???????i????§??????¨????????±???????????¢?´¢?????????
			antDfs(i);
		}
	}

	// ??????
	print();
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	cin >> n;
	
	M.resize(n + 1, vi(n + 1));
	D.resize(n + 1);
	F.resize(n + 1);

	// ??¢?´¢??¶??????????????? (?????¢?´¢)
	searchStatus.resize(n + 1, -1);

	
	int u, k, v;
	REP3(i, 1, n) {
		cin >> u >> k;
		REP3(j, 1, k) {
			cin >> v;
			M[u][v] = 1;
		}
	}

	solve();
	return 0;
}

C++: #include "bits/stdc++.h"
#include "math.h"
 
using namespace std;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<int> vin;
typedef pair<ll,ll> P;
typedef vector<P> vp;
#define rep(i,a,b) for(ll i=(a);i<(b);++i)
#define SIZE(a) int((a).size())
#define out(a) cout<<(a)<<endl;
const int INF=INT_MAX;
const int MAX = 510000;
const ll MOD = 1000000007;
vll d(100),f(100);
ll t=0;
void dfs(vvll g,vb &v,ll x){
  v[x]=true;
  d[x]=++t;
  
  rep(i,0,g[x].size()){
    if(!v[g[x][i]]){
      dfs(g,v,g[x][i]);
    }
  }
  f[x]=++t;
  
}
int main(){
  ll n;cin>>n;
  vvll g(n,vll(0));
  vb visited(n,false);
  rep(i,0,n){
    ll m,k;cin>>m>>k;
    m--;
    rep(j,0,k){
      ll x;cin>>x;
      g[m].push_back(--x);
    }
  }
  rep(i,0,n){
    if(!visited[i]){
      dfs(g,visited,i);
    }
  }
  
  rep(i,0,n){
    cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
  }
}

C++: 
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <cstring>
#include <stack>
#define fre freopen("//home//yanjiewei//CLionProjects//cin.txt", "r", stdin)


using namespace std;

int map[105][105], vis[105];
stack <int> s;

int main(){
//    fre;
    memset(map, 0, sizeof(map));
    memset(vis, 0, sizeof(vis));
    int n;
    cin>> n;
    int u, k, v;
    for(int i = 0; i < n; i++){
        cin>> u;
        cin>> k;
        while(k--){
            cin>> v;
            map[u][v] = 1;
        }
    }
    int t = 1, now = 1;
    int d[105], f[105];
    s.push(1), d[1] = t, vis[1] = 1;
    while(!s.empty()){
        int p = 0;
        now = s.top();
        for(int i = 1; i <= n; i++){
            if(map[now][i] == 1 && vis[i] == 0) {
                s.push(i);
                t++, d[i] = t;
                vis[i] = 1;
                p++;
                break;
            }
        }
        if(p == 0){
            int out = s.top();
            s.pop();
            t++, f[out] = t;
        }
    }
    for(int i = 1; i <= n; i++){
        cout<< i<< ' '<< d[i]<< ' '<< f[i]<< endl;
    }
    return 0;
}