Go: package main

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

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	num, _ := strconv.Atoi(sc.Text())
	nodes := make(map[int]*node)

	for i := 0; i < num; i++ {
		sc.Scan()
		id, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		nodeNum, _ := strconv.Atoi(sc.Text())
		n := node{id, make([]int, 0), 0, 0}
		for j := 0; j < nodeNum; j++ {
			sc.Scan()
			nid, _ := strconv.Atoi(sc.Text())
			n.nexts = append(n.nexts, nid)
		}
		nodes[id] = &n
	}

	s := Stack{}
	for i := 1; i < len(nodes)+1; i++ {
		if nodes[i].s != 0 {
			continue
		}
		walk(i, &nodes, s)
	}
	for i := 1; i < len(nodes)+1; i++ {
		fmt.Printf("%v %v %v\n", (*nodes[i]).id, (*nodes[i]).s, (*nodes[i]).e)
	}
}

var time int

func walk(nid int, nodes *map[int]*node, s Stack) {
	n := (*nodes)[nid]
	if n.s != 0 {
		return
	}
	time++
	n.s = time
	s.Push(n)
	for _, v := range n.nexts {
		walk(v, nodes, s)
	}
	time++
	n.e = time
}

type node struct {
	id    int
	nexts []int
	s     int
	e     int
}

// Stack is Stack
type Stack struct {
	stack []interface{}
}

// Push new value
func (stack *Stack) Push(val interface{}) {
	stack.stack = append(stack.stack, val)
}

// Pop new value
func (stack *Stack) Pop() interface{} {
	val := stack.stack[len(stack.stack)-1]
	stack.stack = stack.stack[0 : len(stack.stack)-1]
	return val
}

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

using namespace std;

const int MAX = 101;

vector<int> G[MAX];
int d[MAX], f[MAX];
int *T;

void dfs(int u) {

    if (!d[u]) d[u] = ++(*T);

    for (int v : G[u]) {
        if (!d[v]) d[v] = ++(*T);
        dfs(v);
    }

    if (!f[u]) f[u] = ++(*T);
}

int main() {

    int n;
    cin >> n;

    int t = 0;
    T = &t;
    fill(d, d + MAX, 0);
    fill(f, f + MAX, 0);

    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v;
            cin >> v;
            G[u].push_back(v);
        }
    }

    for (int i = 1; i <= n; i++) {
        if (!d[i]) dfs(i);
    }


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

C++: #include <iostream>
#include <map>
#include <vector>

using namespace std;
struct node {
    node() {};
    node(int i, int n, int* xs) : id {i}, ns {vector<int>(xs, xs+n)} {
        delete xs;
    };
    int id;
    vector<int> ns;
    int in_time;
    int out_time;
};

int dfs(map<int, node*> graph, int time, int id){
    node* n = graph[id];
    if(n->in_time > 0){
        return time;
    }
    n->in_time = ++time;
    vector<int> ns = n->ns;
    for(auto it = ns.begin(); it != ns.end(); ++it){
        time = dfs(graph, time, *it);
    }
    n->out_time = ++time;
    return time;
}

int main(){
    int n;
    cin >> n;
    map<int, node*> graph {};
    int st = 1000000000;
    for(int i = 0; i < n; ++i){
        int id;
        cin >> id;
        st = min(st, id);
        int k;
        cin >> k;
        int* ns = new int[k];
        for(int j = 0; j < k; ++j){
            cin >> ns[j];
        }
        graph[id] = new node(id, k, ns);
    }
    int time = 0;
    for(auto it = graph.begin(); it != graph.end(); ++it){
        pair<int, node*> p = *it;
        if(p.second->in_time){
            continue;
        }
        time = dfs(graph, time, p.first);
    }
    for(auto it = graph.begin(); it != graph.end(); ++it){
        pair<int, node*> p = *it;
        cout << p.first << ' ' << p.second->in_time << ' ' << p.second->out_time << endl;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)
#define WHITE 0
#define GRAY 1
#define BLACK 2
vector<vector<int>> M(100, vector<int>(100));
vector<int> C(100);
int n, tt;
vector<int> ST(100), PT(100);

int next(int u) {
  rep(i, n) {
    if (M.at(u).at(i) == 1 && C.at(i) == WHITE) {
      return i;
    }
  }
  return -1;
}

void dfs_visit(int u) {
  stack<int> S;
  S.push(u);
  ST.at(u) = ++tt;
  C.at(u) = GRAY;
  while (S.size() > 0) {
    int t = S.top();
    int v = next(t);
    if (v!=-1) {
      if (C.at(v) == WHITE) {
        S.push(v);
        ST.at(v) = ++tt;
        C.at(v) = GRAY;
      }
    } else {
      S.pop();
      PT.at(t) = ++tt;
      C.at(t) = BLACK;
    }
  }
}

void dfs() {
  tt = 0;
  rep(u, n) if (C.at(u) == WHITE) dfs_visit(u);
}

int main() {
  cin >> n;
  rep(i, n) {
    int id, k; cin >> id >> k;
    rep(j, k) {
      int num; cin >> num;
      M.at(id-1).at(num-1) = 1;
    }
  }
  dfs();

  rep(i,n) cout << i+1 << " " << ST.at(i) << " " << PT.at(i) << endl;
  return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <stack>
using namespace std;
const int maxx = 110;
int n, m[maxx][maxx];
int u, num, v;
int d[maxx], f[maxx];
int flag[maxx];
int nowtime = 1;

void dfs(int u) {

	// ??\?????¶??´
	flag[u] = 1;
	d[u] = nowtime++;
	for (int i = 1; i <= n; i++) {
		if (flag[i] == 0 && m[u][i] == 1) {
			dfs(i);
		}
	}
	//????????¶??´
	f[u] = nowtime++;
}

int main()
{

	scanf("%d", &n);
	memset(m, 0, sizeof(m));
	memset(f, 0, sizeof(f));
	for (int i = 1; i <= n; i++) {
		scanf("%d %d", &u, &num);
		for (int j = 1; j <= num; j++) {
			scanf("%d", &v);
			m[u][v] = 1;
		}
	}
	for (int i = 1; i <= n; i++) {
		if(flag[i] == 0)
			dfs(i);
	}
	for (int i = 1; i <= n; i++) {
		printf("%d %d %d\n", i, d[i], f[i]);
	}
	return 0;
}

C++: #include<iostream>
#include<cstring>
#include<vector>
#define rep(i, n) for (int i = 0; i < n; i++)
#define rrep(i, n) for (int i = n - 1; i >= 0; i--)
using namespace std;
//using Graph = vector<vector<int>>;
typedef long long ll;
typedef pair<long long,int> P;


int n, t = 0;
vector<int> g[105];
bool seen[105];
int d[105], f[105];

void dfs(int v){
    seen[v] = true;
    d[v] = t;
    for(int nv : g[v]){
        if(seen[nv]) continue;
        t++;
        dfs(nv);
    }
    t++;
    f[v] = t;
}

int main(){
    cin >> n;
    rep(i, n){
        int a, b;
        cin >> a >> b;
        rep(j, b){
            int c;
            cin >> c;
            g[a].push_back(c);
        }
    }
    rep(k, n) g[0].push_back(k + 1);

    memset(seen, 0, sizeof(seen));
    dfs(0);

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

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <cctype>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <functional>

using namespace std;
using ll = long long int;
#define rep(i,n) for(int i = 0; i < n; i++)
#define FOR(i, a, b)  for(int i = (a); i < (b) ; i++)

#define pb push_back
#define SORT(v,n) sort(v, v+n)
#define ALL(x) (x).begin(),(x).end()
#define debug(x) cerr << #x << ": " << x << '\n'
#define elif else if
#define itn ll
#define int ll
const int INF = 100100100;
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;
///                →,↑,←,↓,↗,↖,↙,↘
int dx[8] = { 1, 0, -1, 0, 1, -1, -1, 1 };
int dy[8] = { 0, 1, 0, -1, 1, 1, -1, -1 };

static const int N = 100;
static const int White = 0;
static const int Gray = 1;
static const int Black = 2;
int d[N], f[N],tt;
int color[N],n,M[N][N];


void dfs_visit(int u) {
	int v;
	d[u] = ++tt;
	color[u] = Gray;
	rep(v,n){
		if (M[u][v] == 0) continue;
		if (color[v] == White) dfs_visit(v);
	}
	color[u] = Black;
	f[u] = ++tt;
}

void dfs() {
	int u;
	rep(u, n)color[u] = White;
	rep(u, n) {
		if (color[u] == White) dfs_visit(u);
	}
	rep(u, n) {
		cout << u + 1 << ' ' << d[u] << ' ' << f[u] << '\n';
	}
}

signed main() {
	ios::sync_with_stdio(false);
	cin >> n;
	int i;
	rep(i, n) {
		int u, k, v;
		cin >> u >> k;
		u--;
		int j;
		rep(j, k) {
			cin >> v;
			v--;
			M[u][v] = 1;
		}
	}
	dfs();
	return 0;
}