Go: package main

/*
深さ優先探索
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		ints := eGetInts(scanner)
		num, vcount := ints[0], ints[1]
		g[i] = make([]int, vcount)
		for j := 0; j < vcount; j++ {
			g[num][j] = ints[j+2]
		}
	}
	hist := make([]struct{ d, f int }, n+1)
	t := 0
	var visit func(int)
	visit = func(num int) {
		if hist[num].d == 0 {
			stack := []int{}
			t++
			hist[num].d = t
			stack = append(stack, num)
			for len(stack) > 0 {
				// トップを訪問する
				top := stack[len(stack)-1]
				for i := 0; i < len(g[top]); i++ {
					if hist[g[top][i]].d == 0 {
						t++
						hist[g[top][i]].d = t
						stack = append(stack, g[top][i])
						goto endloop
					}
				}
				// 訪問場所がなくなったら
				// pop
				stack = stack[0 : len(stack)-1]
				t++
				hist[top].f = t
			endloop:
			}
		}
	}
	for i := 1; i < n+1; i++ {
		visit(i)
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, hist[i].d, hist[i].f)
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <utility>
#include <iostream>
#include <algorithm>
#include <functional>
#include <unordered_map>
#include <unordered_set>

using namespace std;

#define ll long long
#define ull unsigned long long
#define INF (1 << 30)
#define LLINF (1LL << 62)
#define MOD7 1000000007
#define MOD9 1000000009
#define eps 1e-9
#define P pair<int, int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pul pair<ull, ull>
#define all(a) (a).begin(), (a).end()
#define FOR(i,a,b) for (int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);--i)
#define REP(i,n) for (int i=0;i<(n);++i)
#define RREP(i,n) for (int i=(n)-1;i>=0;--i)

void YES() { cout << "YES" << endl; }
void NO() { cout << "NO" << endl; }
void Yes() { cout << "Yes" << endl; }
void No() { cout << "No" << endl; }
void yes() { cout << "yes" << endl; }
void no() { cout << "no" << endl; }

template<class T>
class DirectedGraph {
public:
	class Edge {
	public:
		int to;
		T cost;

		Edge(int t, T c) : to(t), cost(c) {}

		bool operator<(const Edge& right) const {
			return cost == right.cost ? to < right.to : cost < right.cost;
		}
	};

	vector<vector<Edge>> G;
	int V;

	DirectedGraph(int n = 0) {
		resize(n);
	}

	void resize(int n) {
		V = n;
		G.resize(n);
	}

	void addEdge(int from, int to, T cost = NULL) {
		int v = max(from, to);
		if (v >= V)
			resize(v + 1);
		G[from].push_back(Edge(to, cost));
	}


	int t = 1;
	vector<pii> stamp;
	vector<bool> visit;
	void dfs(int s) {
		visit.resize(V);
		stamp.resize(V);
		calcDfs(s);
	}

	void calcDfs(int s) {
		if (visit[s])
			return;

		stamp[s].first = t++;

		visit[s] = true;
		for (int i = 0; i < G[s].size(); ++i) {
			calcDfs(G[s][i].to);
		}

		stamp[s].second = t++;
	}

	vector<int> bfs() {

	}
};

int main() {
	DirectedGraph<int> g;
	int n, id, k, to;
	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> id >> k;
		while (k--) {
			cin >> to;
			g.addEdge(id, to);
		}
	}

	for (int i = 1; i <= n; ++i)
		g.dfs(i);

	for (int i = 1; i <= n; ++i) {
		printf("%d %d %d\n", i, g.stamp[i].first, g.stamp[i].second);
	}

	return 0;
}

C++: #include <iostream>
#include <stack>
using namespace std;
static const int N=101;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;

int M[N][N]={0};
int n;
int color[N]={WHITE},one[N],two[N];
int tt=0,aaa[N]={1};

int next(int num){
    for(int i=aaa[num];i<=n;i++){
        aaa[num]=i+1;
        if(M[num][i]) return i;
    }
    return -1;
}

void dfs_visit(int r){
    stack<int> S;
    S.push(r);
    color[r]=GRAY;
    one[r]=++tt;
    
    while(!S.empty()){
        int u=S.top();
        int v=next(u);
        if(v!=-1){
            if(color[v]==WHITE){
                color[v]=GRAY;
                one[v]=++tt;
                S.push(v);
            }
        }else{
            S.pop();
            color[u]=BLACK;
            two[u]=++tt;
        }
    }
}

void dfs(){
    for(int i=1;i<=n;i++){
        if(color[i]==WHITE) dfs_visit(i);
    }
    for(int i=1;i<=n;i++){
        cout << i << " " << one[i] << " " << two[i] << endl;
    }
}




int main(void){
    cin >> n;
    for(int i=0;i<n;i++){
        int u,k;
        cin >> u >> k;
        for(int j=0;j<k;j++){
            int v;
            cin >> v;
            M[u][v]=1;
        }
    }
    
    dfs();

    return 0;
}

C++: #include<bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < (n); ++i)

using namespace std;
using ll = long long;
using v1 = vector<int>;
using vl = vector<long long>;
using v2 = vector<vector<int>>;
using v3 = vector<vector<char>>;

int t = 0;
int n;

void dfs_v(v2& a, v2& b, int p){
	p--;
	if(a.at(p).at(0) == -1){
		return;
	}
	b.at(p).push_back(++t);
	a.at(p).at(0) = -1;
	rep(i, a.at(p).at(1)){
		int np = a.at(p).at(2+i);
		dfs_v(a, b, np);
	}
	b.at(p).push_back(++t);
}
void dfs(v2& a, v2& b){
	rep(i, n){
		if(a[i][0] != -1){
			dfs_v(a, b, a[i][0]);
		}
	}
}

int main(){
	cin >> n;
	v2 a(n, v1(0));
	v2 b(n, v1(0));
	rep(i, n){
		int m;
		cin >>m;
		a[i].push_back(m);
		b[i].push_back(m);
		int x;
		cin >> x;
		a.at(i).push_back(x);
		rep(j, x){
			int y;
			cin >> y;
			a.at(i).push_back(y);
		}
	}
	dfs(a, b);
	rep(i, n){
		rep(j, 3){
			cout << b[i][j];
			if(j != 2) cout << " ";
			else cout << endl;
		}
	}
}

C++: #include<cstdlib>
#include<cstdio>
#include<algorithm>
#include<vector>
using namespace std;
const int MAXN = (int)1e2 + 10;

int n;
vector<int> g[MAXN];
int vis[MAXN];
int st[MAXN],en[MAXN];
int clk;

void DFS(int u){
    vis[u]=1;
    st[u]=++clk;
    for(int i=0;i<g[u].size();i++){
        int v=g[u][i];
        if(vis[v]) continue;
        DFS(v);
    }
    en[u]=++clk;
}

void work(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        int u,k; scanf("%d%d",&u,&k);
        while(k--){
            int v; scanf("%d",&v);
            g[u].push_back(v);
        }
        sort(g[u].begin(),g[u].end());
    }
    for(int i=1;i<=n;i++)if(!vis[i]) DFS(i);
    for(int i=1;i<=n;i++) printf("%d %d %d\n",i,st[i],en[i]);
}

int main(){
    work();
    return 0;
}