Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}

func getNextUint64(scanner *bufio.Scanner) uint64 {
	i, _ := strconv.ParseUint(getNextString(scanner), 10, 64)
	return i
}

func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}

func main() {
	fp := os.Stdin
	wfp := os.Stdout
	cnt := 0

	if os.Getenv("MASPY") == "ますピ" {
		fp, _ = os.Open(os.Getenv("BEET_THE_HARMONY_OF_PERFECT"))
		cnt = 1
	}
	if os.Getenv("MASPYPY") == "ますピッピ" {
		wfp, _ = os.Create(os.Getenv("NGTKANA_IS_GENIUS10"))
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(wfp)
	solve(scanner, writer)
	for i := 0; i < cnt; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
	writer.Flush()
}

func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	n := getNextInt(scanner)
	g := graph{}
	g.ee = make([]Edges, n)
	g.visited = make([]bool, n)
	g.found = make([]int, n)
	g.leave = make([]int, n)
	for i := 0; i < n; i++ {
		u := getNextInt(scanner) - 1
		k := getNextInt(scanner)
		for j := 0; j < k; j++ {
			v := getNextInt(scanner) - 1
			g.ee[u] = append(g.ee[u], Edge{
				to: v,
				id: u,
			})
		}
	}
	for i := 0; i < n; i++ {
		sort.Sort(g.ee[i])
	}
	for i := 0; i < n; i++ {
		if g.visited[i] {
			continue
		}
		g.dfs(i)
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d %d", i+1, g.found[i], g.leave[i]))
	}
}

// Edge ...
type Edge struct {
	to, id int
}

type Edges []Edge

func (a Edges) Len() int           { return len(a) }
func (a Edges) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
func (a Edges) Less(i, j int) bool { return a[i].id < a[j].id }

type graph struct {
	ee           []Edges
	t            int
	n            int
	visited      []bool
	found, leave []int
}

func (g *graph) dfs(i int) {
	g.visited[i] = true
	g.t++
	g.found[i] = g.t
	for _, e := range g.ee[i] {
		if g.visited[e.to] {
			continue
		}
		g.dfs(e.to)
	}
	g.t++
	g.leave[i] = g.t
}

C++: #include <stdio.h>

#define VerticesNum 100
typedef unsigned int uint;

struct output
{
    uint uDiscoverTime;
    uint uFinTime;
}Output;

struct output gstOutput[VerticesNum];
uint uTotalTime = 1;

void DepthFirstSearch(uint pGraph[][VerticesNum], uint uSize, uint uRoot)
{
    if(gstOutput[uRoot].uDiscoverTime == 0)
    {
        gstOutput[uRoot].uDiscoverTime = uTotalTime++;
    }
    else
    {
        return;
    }
    
    for(uint i = 0; i < uSize; i++)
    {
        if((pGraph[uRoot][i] == 1) && (gstOutput[i].uDiscoverTime == 0 ))
        {
            DepthFirstSearch(pGraph, uSize, i);
        }
    }
    gstOutput[uRoot].uFinTime = uTotalTime++;
    
    return;
}

int main(void){
    uint arGraph[VerticesNum][VerticesNum] = {};
    
    uint uVertices;
    scanf("%u", &uVertices);
    
    for(uint i = 0; i < uVertices; i++)
    {
        uint uVertexIdx;
        uint OutDegree;
        scanf("%u", &uVertexIdx);
        scanf("%u", &OutDegree);
        for(uint j = 0; j < OutDegree; j++)
        {
            uint AdjacentVertex;
            scanf("%u", &AdjacentVertex);
            arGraph[uVertexIdx - 1][AdjacentVertex - 1] = 1; 
        }
    }
    /*
    for(uint i = 0; i < uVertices; i++)
    {
        for(uint j = 0; j < uVertices; j++)
        {
            printf("%u", stGraph[i][j]);
            (j < (uVertices - 1))
                ? printf(" ")
                : printf("\n");
        }
    }
    */
    for(uint uRoot = 0; uRoot < uVertices; uRoot++)
    {
        DepthFirstSearch(arGraph, uVertices, uRoot);
    }
    
    for(uint i = 0; i < uVertices; i++)
    {
        printf("%d %d %d\n", i + 1, gstOutput[i].uDiscoverTime, gstOutput[i].uFinTime);
    }
    
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using pii=pair<int,int>;
using ll=long long;
using pll=pair<ll,ll>;

#define fi first
#define se second
#define pb push_back
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define MOD 1000000007

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

int N;
vector<vector<int>> G(110, vector<int>());
vector<int> d(110), f(110), k(110);
vector<bool> visited(110, false);
int t = 0;

void dfs(int v) {
	visited[v] = true;
	d[v] = t;
	//cout << v << " d[" << v << "]:" << d[v] << " " << t << endl;
	rep(i, k[v]) {
		if(visited[G[v][i]]) continue;
		t++;
		//cout << G[v][i] << " " << t << endl;
		dfs(G[v][i]);
		//cout << G[v][i] << " " << t << endl;
	}
	t++;
	f[v] = t;
	//cout << v << " f[" << v << "]:" << f[v] << endl;
	return;
}

int main() {
	cin >> N;
	rep(i,N) {
		int u;
		cin >> u >> k[i];
		G[i] = vector<int>(k[i]);
		rep(j,k[i]) {
			cin >> G[i][j];
			G[i][j]--;
		}
	}
	rep(i,N) {
		if(visited[i] == false) t++,dfs(i);
	}
	rep(i,N) cout << i+1 << " " << d[i] << " " << f[i] << endl;


  return 0;
}

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

int G[105][105]={};
int d[105]={},f[105]={};
int N,T=0;

void Gprint(int n){
    cout<<"\\|";
    for(int i=0; i<n; i++)cout<<i+1;
    cout<<endl;
    for(int i=0; i<n+2; i++)cout<<"-";
    cout<<endl;
    for(int i=0; i<n; i++){
        cout<<i+1<<"|";
        for(int j=0; j<n; j++){
            cout<<G[i][j];
        }
        cout<<endl;
    }
}

void dfs(int n){
    if(d[n])return;
    d[n]=++T;
    for(int i=0; i<N; i++){
        if(G[n][i])dfs(i);
    }
    f[n]=++T;
}

int main(){
    int u,k,v;

    cin>>N;
    for(int i=0; i<N; i++){
        cin>>u>>k;
        for(int j=0; j<k; j++){
            cin>>v;
            G[u-1][v-1]=1;
        }
    }

   Gprint(N);

    for(int i=0; i<N; i++)
        dfs(i);

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

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

using namespace std;

//4
//1 1 2
//2 1 4
//3 0
//4 1 3

//1 1 8
//2 2 7
//3 4 5
//4 3 6

const int MAX = 100;

int n;

int t = 0;

int G[MAX + 1][MAX + 1];
int d[MAX + 1];
int f[MAX + 1];

int color[MAX + 1];
int WHITE = 0;
int GRAY = 1;
int BLACK = 2;

void dfs(int v) {
	color[v] = GRAY;
	d[v] = ++t;

	for (int i = 1; i <= n; ++i) {
		if (G[v][i] == 1 && color[i] == WHITE)
			dfs(i);
	}

	color[v] = BLACK;
	f[v] = ++t;
}

int main() {

	scanf("%d", &n);

	for (int i = 0; i <= n; ++i) {
		for (int j = 0; j <= n; ++j)
			G[i][j] = 0;
	}

	for (int i = 1; i <= n; ++i) {
		int u, k;
		scanf("%d %d", &u, &k);
		for (int j = 0; j < k; ++j) {
			int v;
			scanf("%d", &v);
			G[i][v] = 1;
		}
	}

	dfs(1);

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

	return 0;

}