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()
}

Python: def visit(u):
    global visit_color, d, f, t
    color[u] = GRAY
    d[u] += t
    t += 1
    for v in range(n):
        if (M[u][v] == 0):
            continue
        else:
            if (color[v] == WHITE):
                visit(v)
    color[u] = BLACK
    f[u] = t
    t += 1

n = int(input())
M = [[0 for i in range(n)] for i in range(n)]
for i in range(n):
    tmp = list(map(int, input().split()))
    for j in range(tmp[1]):
        M[tmp[0]-1][tmp[j+2]-1] = 1

for u in range(n):
    if (color[u] == WHITE):
        visit(u)
for u in range(n):
    print(str(u+1), str(d[u]), str(f[u]), sep = " ")

Python: from sys import stdin
n = int(stdin.readline())
M = [list(map(int, stdin.readline().split()[2:])) for i in range(n)]
sndf = [[False, i] for i in range(1, n + 1)]
tt = 0
def dfs(u):
    global tt
    sndf[u][0] = True
    tt += 1
    sndf[u].append(tt)
    for v in M[u]:
        v -= 1
        if not sndf[v][0]:
            dfs(v)
    tt += 1
    sndf[u].append(tt)
for i in range(0, n):
    if not sndf[i][0]:
        dfs(i)
    print(*sndf[i][1:])

Python:    #depth first
N=int(input())
V=[]
a=[0]
for i in range(N):
    V.append([int(i) for i in input().split()])
    w=V[i][2:]
    w.sort()
    V[i]=V[i][:2]+w
    a.append(0)
V=sorted(V,key=lambda x:x[0])
c=1
t=1
i=0
r=[1]
a[1]=1
p=[[1,t]]
q=[]
while t<N*2:
    j=2
    while t<N*2 and j-2<V[i][1] and V[i][1]>0 and a[V[i][j]]==1:
        j+=1
    t+=1
    if j-2<V[i][1]:
        a[V[i][j]]=1
        c+=1
        r.append(V[i][j])
        p.append([V[i][j],t])
        i=V[i][j]-1
    else:
        q.append(p[-1]+[t])
        r.pop(-1)
        p.pop(-1)
        if len(r)>0:
            i=r[-1]-1
        else:
            j=1
            while j<N and a[j]==1:
                j+=1
            if j<N:
                t+=1
                i=j-1
                r.append(j)
                p.append([j,t])
q=sorted(q,key=lambda x:x[0])
for i in range(N):
    for j in range(3):
        q[i][j]=str(q[i][j])
    print(" ".join(q[i]))

Python: def DFS(num):
    global time
    time +=1
    color[num]="gray"
    D[num][0]=time
    for i in M[num]:
        if color[i]=="white":
            DFS(i)
    color[num]="black"
    time +=1
    D[num][1]=time


n=int(input())
M=[[] for _ in range(n+1)]
for i in range(n):
    for j in list(map(int,input().split()))[2:]:
        M[i+1].append(j)
color=["white" for _ in range(n+1)]
D=[[0,0] for _ in range(n+1)]
time=0
for i in range(n):
    if color[i+1]=="white":
        DFS(i+1)

for i in range(n):
    print(i+1,*D[i+1])

Python: n=int(input())

next=[[] for i in range(n)]
for i in range(n):
	l=list(map(int,input().split()))
	u=l[0]
	k=l[1]
	for j in range(2,k+2):
		next[u-1].append(l[j]-1)

stk=[]
stk.append(0)
time=1
d=[0 for i in range(n)]
f=[0 for i in range(n)]
know=[0 for i in range(n)]

def dfs(x):
	global time
	know[x]=1
	d[x]=time
	time+=1
	for n in next[x]:
		if know[n]==0:
			dfs(n)
	f[x]=time
	time+=1
	
for i in range(n):
	if know[i]==0:
		dfs(i)

for i in range(n):
	out=[]
	out.append(i+1)
	out.append(d[i])
	out.append(f[i])
	print(*out)

Python: # -*- coding: utf-8 -*-

import sys
sys.setrecursionlimit(10 ** 9)
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
INF=float('inf')

N=INT()
nodes=[[] for i in range(N)]
for i in range(N):
    l=LIST()
    u=l[0]
    l=l[2:]
    for v in l:
        nodes[u-1].append(v-1)
    nodes[u-1].sort()

ans=[[0]*2 for i in range(N)]
visited=[False]*N
time=0
def rec(u):
    if visited[u]:
        return
    visited[u]=True
    global time
    time+=1
    ans[u][0]=time
    for v in nodes[u]:
        rec(v)
    time+=1
    ans[u][1]=time

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