Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

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

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	ans := make([][2]int, N)
	time := 0
	found := make(map[int]bool)
	var dfs func(cur int)
	dfs = func(cur int) {
		time++
		ans[cur][0] = time
		found[cur] = true
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if !found[next] {
				dfs(G[cur][i])
			}
		}
		time++
		ans[cur][1] = time
	}
	for i := 0; i < N; i++ {
		if !found[i] {
			dfs(i)
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprint(wtr, i+1)
		for j := 0; j < 2; j++ {
			fmt.Fprint(wtr, " ")
			fmt.Fprint(wtr, ans[i][j])
		}
		fmt.Fprintln(wtr)
	}
	wtr.Flush()
}

C++: #include <stdio.h>
#include <string.h>
#define N 110
int n;
int m[N][N];
int used[N];
int time = 1;
int start[N];
int end[N];
void dfs(int u){
    used[u] = 1;
    start[u] = time++;
    for(int v = 1; v <= n; v++){
        if(used[v] == 0 && m[u][v]){
            dfs(v);
        }
    }
    end[u] = time++;
}
int main(){
    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++) used[i] = 0;
    scanf("%d", &n);
    for(int p = 0; p < n; p++){
        int node, k;
        scanf("%d %d", &node, &k);
        for(int i = 0; i < k; i++){
            int b;
            scanf("%d", &b);
            m[node][b] = 1;
        }
    }

    for(int i = 1; i<= n; i++) if(used[i] == 0) dfs(i);
    for(int i = 1; i <= n; i++){
        printf("%d %d %d\n", i, start[i], end[i]);
    }
    return 0;
}

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

#define MAX 100

#define WHITE 0
#define GRAY 1
#define BLACK 2

int T;
int N;

int M[MAX][MAX];
int D[MAX], F[MAX], C[MAX];

void dfs(int u)
{
    C[u] = GRAY;
    D[u] = ++T;

    for (int i = 0; i < N; i++)
    {
        if(M[u][i] == 1 && C[i] == WHITE)
        {
            dfs(i);
        }        
    }
    C[u] = BLACK;
    F[u] = ++T;
}

int main ()
{
    cin >> N;

    for (int i = 0; i < N; i++)
    {
        D[i] = 0;
        F[i] = 0;
        C[i] = WHITE;
        
        for (int j = 0; j < N; j++)
        {
            M[i][j] = 0;
        }
    }

    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--;
            M[u][v] = 1;
        }
    }

    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            if (j > 0)
                cout << " ";
            cout << M[i][j];
        }
        cout << endl;
    }

    T = 0;

    for (int i = 0; i < N; i++)
    {
        if (C[i] == WHITE)
        {
            dfs(i);
        }
    }

    /*
    stack<int> *S = new stack<int>;


    S->push(0);
    C[0] = GRAY;
    D[0] = ++time;

    while (S->size() > 0)
    {
        int u = S->top();
        int v = -1;

        // next 
        for (int i = 0; i < N; i++)
        {
            if (M[u][i] == 1)
            {
                if (C[i] == WHITE)
                {
                    v = i;
                    break;
                }
            }
        }

        if (v != -1)
        {
            C[v] = GRAY;
            D[v] = ++time;
            S->push(v);
        }
        else
        {
            S->pop();
            C[u] = BLACK;
            F[u] = ++time;
        }
    }
*/

    for (int i = 0; i < N; i++)
    {
        cout << i + 1 << " " << D[i] << " " << F[i] << endl;
    }
    return 0;
}

C++: #include <stdio.h>
#define WHITE 0
#define GRAY  1
#define BLACK 2
int color[100];
int d[100],f[100];
int G[100][100];
int n, time = 0;
void dfs(int u)
{
    color[u] = 1;
    d[u] = ++time;
    for (int i = 0; i < n; i++)
    {
        if (G[u][i]==1 && color[i] == 0)
        {
            dfs(i);
        }
    } 
    color[u] = 2;
    f[u] = ++time;
    return;
}
int main()
{
    int k,u,v;
    scanf("%d",&n);
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            G[i][j] = 0; 
        }  
    } 
    for (int i = 0; i < n; i++)
    {
        scanf("%d %d",&u,&k);
        for (int j = 0; j < k; j++)
        {
            scanf("%d",&v);
            G[u-1][v-1] = 1;
        } 
    } 
    for (int i = 0; i < n; i++)
    {
        color[i] = 0; 
        d[i] = 0;
        f[i] = 0;
    } 
    for (int i = 0; i < n; i++)
    {
        if(color[i]==0) dfs(i); 
    } 
    for (int i = 0; i < n; i++)
    {
        printf("%d %d %d\n", i+1, d[i], f[i]); 
    } 
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int n, t;
vector<int> G[110];
vector<int> d(110), f(110), visited(110, -1); 

void dfs_visit(int u) {
    visited[u] = 0;
    d[u] = ++t;
    for (int v = 0; v < G[u].size(); v++) {
        if (visited[G[u][v]] == -1) {
            dfs_visit(G[u][v]);
        }
    }
    visited[u] = 1;
    f[u] = ++t;
}

void dfs() {
    for (int u = 0; u < n; u++) visited[u] = -1;
    t = 0;
    for (int u = 0; u < n; u++) {
        if (visited[u] == -1) dfs_visit(u);
    }
    for (int u = 0; u < n; u++) {
        cout << u + 1 << " " << d[u] << " " << f[u] << endl;
    }
}

int main() {
    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;
            G[u-1].push_back(v-1);
        }
    }
    dfs();
}