Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve(parseProblem())
}

type graph struct {
	size  int
	edges [][]int
}

func parseProblem() *graph {
	n := scanInt(sc)
	g := &graph{
		size:  n,
		edges: make([][]int, n),
	}
	for i := 0; i < g.size; i++ {
		_ = scanInt(sc)
		k := scanInt(sc)
		g.edges[i] = make([]int, k)
		for j := 0; j < k; j++ {
			g.edges[i][j] = scanInt(sc) - 1
		}
	}
	return g
}

func resolve(g *graph) {
	ds := make([]int, g.size)
	fs := make([]int, g.size)
	time := 0
	for i := 0; i < len(ds); i++ {
		if ds[i] == 0 {
			time++
			time = _dfs(ds, fs, time, g, i)
		}
	}
	for i := 0; i < len(ds); i++ {
		fmt.Println(i+1, ds[i], fs[i])
	}
	return
}

func _dfs(ds, fs []int, time int, g *graph, idx int) int {
	ds[idx] = time
	for _, next := range g.edges[idx] {
		if ds[next] > 0 {
			continue
		}
		time++
		time = _dfs(ds, fs, time, g, next)
	}
	time++
	fs[idx] = time
	return time
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: #include <iostream>
#include<string>
#include<cmath>
#include<algorithm>
#include<cctype>
#include<queue>
#include<stack>
#include<stdio.h>
#include<vector>
#include<set>
#include<map>
#include<array>
#include<iomanip>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;

static const int N=100;
static const int white=0;
static const int gray=1;
static const int black=2;
int color[N],nt[N];
int mp[N][N];
int n,d[N],f[N],tt;
int next(int r){
    
    for(int i=nt[r];i<n;i++){
        nt[r]=i+1;
        if(mp[r][i])return i;
        
    }
    return -1;
    
}

void dfs_visit(int r){
    rep(i,n){nt[i]=0;}
    stack<int> s;
    s.push(r);
    d[r]=++tt;
    color[r]=gray;
    while(!s.empty()){
        int u=s.top();
        int v=next(u);
        if(v!=-1){
            d[v]=++tt;
            color[v]=gray;
            s.push(v);
        }else{
            f[u]=++tt;
            color[u]=black;
            s.pop();
        }
        
        
        
    }
    
    
}



void dfs(){
    tt=0;
    rep(i,n){
        color[i]=white;
    }
    rep(i,n){
        if(color[i]==white){
            dfs_visit(i);
        }
    }
    rep(i,n){
        cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
    }
}


int main(){
    cin>>n;
    rep(i,N){
        rep(i,N){
            mp[i][n]=0;
        }
    }
    rep(i,n){
        int a,b;
        cin>>a>>b;
        a--;
        rep(i,b){
            int c;
            cin>>c;
            c--;
            mp[a][c]=1;
        }
    }
    dfs();
    return 0;
}

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 = 0) {
		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<vector>
using namespace std;
int cnt=1;
void depth(vector< vector<int> > &vv,vector<int> &f,vector<int> &c,int num){
	
	f[num]=cnt;
	cnt++;
	
	for(int i=0; i<vv[num].size(); i++){
		if(vv[num][i]!=0 && f[i]==0){
			depth(vv,f,c,i);
		}
	}

	c[num]=cnt;
	cnt++;

}
int main(){
	int n;
	cin>>n;
	vector< vector<int> > v(n,vector<int> (n,0));
	vector<int> ft(n,0);
	vector<int> ct(n,0);
	int u[n];
	for(int i=0; i<n; i++){
		int k;
		cin>>u[i]>>k;
		for(int j=0; j<k; j++){
			int x;
			cin>>x;
			v[i][x-1]=1;
		}
	}
	for(int i=0; i<n; i++){
		if(ft[i]==0){
			depth(v,ft,ct,i);
		}
		cout<<u[i]<<" "<<ft[i]<<" "<<ct[i]<<endl;
	}
  return 0;
}