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: # -*- coding: utf-8 -*-
"""
Created on Sun Jul  8 10:56:33 2018

@author: maezawa
"""
n = int(input())
adj = [[] for _ in range(n)]
d = [0 for _ in range(n)]
f = [0 for _ in range(n)]

for j in range(n):
    ain = list(map(int, input().split()))
    u = ain[0]
    k = ain[1]
    for i in range(k):
        adj[u-1].append(ain[i+2]-1)
    adj[u-1].sort()
    #print(*adj[u-1])

t = 1
stack = [0]

while stack:
    print(stack)
    current = stack[-1]
    if d[current] == 0:
        d[current] = t
        t += 1
    flag = 0
    for k in adj[current]:
        if d[k] == 0:
            stack.append(k)
            flag = 1
            break
    if flag == 0:
        f[current] = t
        t += 1
        stack.pop()

    #print('current = {}, t = {}'.format(current, t))
    #print('stack', *stack)

for i in range(n):
    print('{} {} {}'.format(i+1, d[i], f[i]))

Python: def DFS(adj, start):
    n = len(adj)
    d = [0] * n
    f = [0] * n
    flag = [0] * n
    S = []
    time = 1

    S.append(start)
    flag[start] = 1
    d[start] = time
    time = time + 1
    
    while flag.count(2) != n: # ??¨????????????????????¢?´¢????????????????????§
        if len(S) != 0:
            u = S.pop()
            v = next(adj, u)
            v = [i for i in v if flag[i] == 0] # v <= ??£??\???????????????????????¢?´¢??????????????????
            if len(v) != 0:
                S.append(u)
                S.append(v[0])
                flag[v[0]] = 1
                d[v[0]] = time
                time = time + 1
            else:
            #??£??\??????????????¨????¨??????????
                flag[u] = 2
                f[u] = time
                time = time + 1

        else:
            u = flag.index(0)
            S.append(u)
            flag[u] = 1
            d[u] = time
            time = time + 1            

    return d, f



def next(adj, u):
    """
    u?????£??\??????????????????????????????????????????
    """
    return [i for i, x in enumerate(adj[u]) if x == 1]
    

def main():
    
    n = int(input())
    adj = [[0 for i in range(n)] for j in range(n)]

    for i in range(n):
        tmp = list(map(int, input().split()))
        u = tmp[0]
        u = u -1
        k = tmp[1]
        v = tmp[2:]
        for j in range(k):
            adj[u][v[j]-1] = 1
    
    d, f = DFS(adj, 0)
    for i in range(n):
        print(i+1, d[i], f[i])

if __name__ == "__main__":
    main()

Python: # -*- coding: utf_8 -*-

level = False
def debug(v):
    if level:
        print(v)

n = int(input())
a = [0]

for i in range(n):
    v = input().split()
    v.pop(0)
    v.pop(0)
    a.append([int(x) for x in v])

debug(a)
stack = [1]
results = [[0 for i in range(2)] for j in range(n + 1)]
results[0][0] = 0
time = 0


def depth_first_search(a, stack):
    debug(a)
    debug(results)
    debug(stack)
    global time
    if len(stack) == 0:
        return

    v = stack.pop()
    if results[v][0] == 0:
        time += 1
        results[v][0] = time

    es = a[v]
    if len(es) == 0 and results[v][1] == 0:
        time += 1
        results[v][1] = time

    if len(es) != 0:
        stack.append(v)
        stack.append(es.pop(0))

    depth_first_search(a, stack)

for i in range(n):
    stack = [i + 1]
    depth_first_search(a, stack)

debug(results)

results.pop(0)

i = 1
for row in results:
    print(str(i) + " " + str(row[0]) + " " + str(row[1]))
    i += 1

Python: time=1
num=0
n=int(input())

A=[[] for i in range(n)]
d=[0 for i in range(n)]
f=[0 for i in range(n)]

for i in range(n):
	a=list(map(int,input().split()))
	for j in range(a[1]):
		A[i].append(a[2+j]-1)

def dfs(q,num):
	global d,f,time
	d[num]=time
	for nx in q[num]:
		if d[nx]==0:
			time+=1
			dfs(q,nx)
	time+=1
	f[num]=time
	

dfs(A,num)

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

Python: def visit(u):
    global 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 i in range(tmp[1]):
        M[tmp[0]-1][tmp[i+2]-1] = 1

WHITE = 0
GRAY = 1
BLACK = 2
color = [WHITE for i in range(n)]
d, f = [0 for i in range(n)]
t = 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 = " ")