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 <iostream>
#include <vector>
#define WHITE 0
#define GRAY 1
#define BLACK 2
using namespace std;

int N, k, tt=0, starttime[100], stoptime[100], color[100]={0};
vector<int> E[100];

void dfsfunc(int node){
    //cout << node << " OKdfsfunc" << endl;
    tt++;
    starttime[node] = tt;
    color[node] = GRAY;
    for(int i=0;i<E[node].size();i++){
        if(color[E[node][i]]==WHITE){
            dfsfunc(E[node][i]);
        }
    }
    tt++;
    stoptime[node] = tt;
    color[node] = BLACK;
}

void dfs(){
    for(int node=0;node<N;node++){
        if(color[node]==WHITE) dfsfunc(node);
    }
    //cout << "OK" << endl;
}

int main(){
    cin >> N;
    for(int i=0;i<N;i++) {
        cin >> k;
        cin >> k;
        //cout << "OK" << endl;
        for(int j=0;j<k;j++) {
            int node;
            cin >> node;
            node--;
            E[i].push_back(node);
        }
    }
    //cout << "OK" << endl;
    dfs();
    for(int i=0;i<N;i++) cout << i+1 << " " << starttime[i] << " " << stoptime[i] << endl; 
}

C++: #include <iostream>
#include <stack>
using namespace std;
static const int N=100;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;

//??¶????????°
int n;
//?????\??????
int M[N][N];
//??°?????¶???????¢????
int color[N];
//??\??¶????????°??¶???
int d[N];
//??\??¶???????????¶???
int f[N];
//??¶???
int tt;
//???????????????????????????????????????
//?????¨?????????????????¨????????\??????????????????
int nt[N];

//????????????????????????u?????????v
int next(int u){
    for(int v=nt[u];v<n;v++){
        nt[u]=v+1;
        if(M[u][v]&&color[v]==WHITE)
            return v;
    }
    return -1;
}

//??¨????????°?????±?????????????´¢
void dfs_visit(int r){
    for(int i=0;i<n;i++)
        nt[i]=0;

    stack<int> S;
    S.push(r);
    color[r]=GRAY;
    //?????°??¶???
    d[r]=++tt;

    while(!S.empty()){
        int u=S.top();
        int v=next(u);
        if(v!=-1){
            color[v] = GRAY;
            d[v] = ++tt;
            S.push(v);
        }
        else{
            //????????????
            S.pop();
            color[u]=BLACK;
            f[u]=++tt;
        }
    }
}

void dfs(){
    //????§????
    for(int i=0;i<n;i++)
        nt[i]=0,color[i]=WHITE;
    tt=0;

    //??\????????????u?????????????????±?????????????´¢
    for(int u=0;u<n;u++)
        if(color[u]==WHITE)
            dfs_visit(u);

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

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

    cin>>n;
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            M[i][j]=0;

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

    dfs();
}

C++: #include "bits/stdc++.h"

using namespace std;

void dfs(int curr, int& ts, const vector<set<int> >& graph
        , vector<int>& d, vector<int>& f) {

    ++ts;
    d[curr] = ts;
    const set<int>& nextNodes = graph[curr];
    for (int n : nextNodes) {
        if (d[n] > 0) {
            continue;
        }
        dfs(n, ts, graph, d, f);
    }
    ++ts;
    f[curr] = ts;
}

void Main() {
    int n;
    cin >> n;
    vector<set<int> > graph(n, set<int>());
    for (int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;
        --u;
        for (int j = 0; j < k; ++j) {
            int v;
            cin >> v;
            --v;
            graph[u].insert(v);
        }
    }

    vector<int> d(n, -1);
    vector<int> f(n, -1);
    int timestamp = 0;
    for (int i = 0; i < n; ++i) {
        if (d[i] < 0) {
            dfs(i, timestamp, graph, d, f);
        }
    }
    for (int i = 0; i < n; ++i) {
        cout << (i + 1) << " " << d[i] << " " << f[i] << endl;
    }
}

int main() {
    std::cout << std::fixed << std::setprecision(15);
    Main();
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

void dfs_visit(int u, int N, vector<vector<int>> &M, vector<string> &color,
               int &tt, vector<int> &start, vector<int> &finish) {
    color[u] = "GRAY";
    tt++;
    start[u] = tt;
    for (int v = 0; v < N; v++) {
        // if (M[u][v] == 0);
        //     continue;
        // cout << v << endl;
        if (M[u][v] == 1 && color[v] == "WHITE")
        {
            dfs_visit(v, N, M, color, tt, start, finish);
        }
    }
    color[u] = "BLACK"; // 訪問完了
    tt++;
    finish[u] = tt;
}

void dfs(int N, vector<vector<int>> &M, vector<string> &color,
         int &tt, vector<int> &start, vector<int> &finish) {

    tt = 0;
    // cout << "hee" << endl;
    for (int u = 0; u < N; u++)
    { // uが未訪問ならば
        if (color[u] == "WHITE") {
            // cout << u << " " << tt << endl;
            dfs_visit(u, N, M, color, tt, start, finish);
        }
    }
    for (int u = 0; u < N; u++) {
        cout << u + 1 << " " << start[u] << " " << finish[u] << endl;
    }
}

int main() {
    int N;
    cin >> N;

    vector<vector<int>> M(N, vector<int>(N, 0));
    vector<string> color(N, "WHITE");
    int tt = 0;
    vector<int> start(N, 0);
    vector<int> finish(N, 0);

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

    dfs(N, M, color, tt, start, finish);
}