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
}

Python: def dfs(u):
    global time
    color[u] = 'Gray'
    time += 1
    d[u] = time
    for v in range(1, n+1):
        if data[u][v] == 0:
            continue
        if color[v] == 'White':
            dfs(v)
    color[u] = 'Black'
    time += 1
    f[u] = time


n = int(input())
A = [list(map(int, input().split()))for _ in range(n)]
data = [[0]*(n+1) for _ in range(n+1)]
color = ['White']*(n+1)
d = [None]*(n+1)
f = [None]*(n+1)
time = 0
for i in A:
    for j in i[2:]:
        data[i[0]][j] = 1

for u in range(1, n+1):
    if color[u] == 'White':
        dfs(u)
for i in range(1, n+1):
    print('{} {} {}'.format(i, d[i], f[i]))

Python: from enum import Enum

class Color(Enum):
  WHITE = 0
  GRAY = 1
  BLACK = 2

def dfs_visit(u, total_time):
  colors[u] = Color.GRAY
  total_time += 1
  d[u] = total_time
  stack.append(u)
  for v in range(N):
    if adj[u][v] == 1 and colors[v] == Color.WHITE:
      total_time = dfs_visit(v, total_time)
  colors[u] = Color.BLACK
  total_time += 1
  f[u] = total_time
  return total_time



def dfs(total_time):
  for i in range(N):
    if colors[i] != Color.WHITE:
      continue
    total_time = dfs_visit(i, total_time)

N = int(input())
L = [list(map(int, input().split())) for i in range(N)]
adj = [[0 for i in range(N)] for j in range(N)]

for i in range(N):
  for node in L[i][2:]:
    adj[i][node-1] = 1

colors = [Color.WHITE for i in range(N)]
stack = []
total_time = 0
d = [0 for i in range(N)]
f = [0 for i in range(N)]

dfs(total_time)

for i in range(N):
  print(i+1, d[i], f[i])

Python: # -*- coding: utf-8 -*-
'''
所要時間は、分位であった。
'''


# ライブラリのインポート
#import re
import sys
input = sys.stdin.readline
#import heapq
#import bisect
import collections
#import math
global time, Ls, Lf, E,LG,c,n
time = 1

def main():
    global time, Ls, Lf, E, LG,c,n
    c = 0
    n = int(input().strip())
    E = [[] for _ in range(n)]
    LG = collections.deque()
    for line in sys.stdin:
        Ltmp = list(map(int, list(line.strip().split())))
        if not Ltmp[1] == 0: 
            E[Ltmp[0]-1] = Ltmp[2:]
    Ls = [0]*n 
    Lf = [0]*n
    dfs(0)
    for i in range(n):
        print(i+1, Ls[i],Lf[i])
    
def dfs(cur):
    global time, Ls, Lf, E, LG,c,n
    LG.append(cur)
    if Ls[cur] == 0: Ls[cur] = time
    time += 1
    for i in range(len(E[cur])):
        check = E[cur][i] - 1
        if Ls[check] == 0: dfs(check)
    if Lf[cur] == 0:
        Lf[cur] = time
    try:
        x = LG.pop()
        if x == cur: x = LG.pop() 
        dfs(x)
    except:
        time += 1
        for i in range(c,n):
            if Ls[i] == 0:
                c = i
                dfs(i) 
    return




    


    
if __name__ == '__main__':
    main()

Python: cin = open(0).read().strip().split('\n')
n = int(cin[0])
g = [list(map(lambda x: int(x)-1, a.split(' ')[2:])) for a in cin[1:]]

first_order = [-1] * n
last_order = [-1] * n
ptr = 1

def dfs(g, seen, idx):
    global first_order, first_order, ptr

    first_order[idx] = ptr
    ptr += 1

    seen[idx] = True
    for i in g[idx]:
        # idxから行ける各頂点について
        if seen[i]: continue
        dfs(g, seen, i)

    last_order[idx] = ptr
    ptr += 1

seen = [False] * n
dfs(g, seen, 0)

# 孤立している頂点対策
for i in range(n):
    if not seen[i]:
        ans = dfs(g, seen, i)

# 出力
for idx, (f, l) in enumerate(zip(first_order, last_order)):
    print(idx+1, f, l)

Python: global t
t = 0

class Node:
    def __init__(self, num, deg, neib):
        self.num = num
        self.deg = deg
        self.neib = neib

def dfs(G, d, f, now): #now:1,2,...
    print("now:",now)
    global t
    t += 1
    print("t:",t)
    if f[now-1] != 0: t -= 1
    else:
        d[now-1] = t
        print("d:",d)
        print("f:",f)
        for i in G[now-1].neib:
            print("i:",i)
            if i != -1:
                print("next")
                dfs(G, d, f, i)
            else:
                print("end of branch")
            
        t += 1
        if f[now-1] == 0:
            f[now-1] = t

        print("f:",f)


dnum = int(input()) #頂点数
N = []
for i in range(dnum):
    data = input().split()
    
    u = int(data[0])
    k = int(data[1])
    if k > 0:
        v = list(map(int, data[2:]))
    else:
        v = [-1]

    node = Node(u,k,v)
    N.append(node)

d = [0]*dnum #find time
f = [0]*dnum #finish time

dfs(N, d, f, 1)

for i in range(dnum):
    print(i+1, d[i], f[i])