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(i):
    for j in range(n):
        if A[i][j] == 1 and d[j] == 0:
            time = time + 1
            d[j] = time
            DFS(j)
    time = time + 1
    f[i] = time

n = int(raw_input())
A = [0] * n
for i in range(n):
    A[i] = [0] * n

for i in range(n):
    value = map(int, raw_input().split())
    u = value[0] - 1
    k = value[1]
    nodes = value[2:]
    for i in range(k):
        v = nodes[i] - 1
        A[u][v] = 1

d = [0] * n
f = [0] * n
time = 1
d[0] = time
DFS(0)

for i in range(n):
    print(str(i + 1) + " " + str(d[0]) + " " + str(f[0]))

Python: from collections import defaultdict

def dfs(here, connect, visited, answer):
    global time
    answer[here][1] = time
    time += 1
    visited[here] = 1
    for c in connect[here]:
        if not visited[c]:
            dfs(c, connect, visited, answer)
    answer[here][2] = time
    time += 1

v_num = int(input())
connect = defaultdict(list)
for _ in range(v_num):
    inp = [int(n) - 1 for n in input().split(" ")]
    connect[inp[0]].extend(sorted(inp[2:]))
answer = [[n + 1 for m in range(3)] for n in range(v_num)]
time = 1
visited = [0 for n in range(v_num)]
dfs(0, connect, visited, answer)
for v in range(v_num):
    print(*answer[v])

Python: from collections import deque
time = 1

def dfs(adj_list, d, f, color, u):

    global time
    S = list()

    S.append(u)
    color[u] = "G"
    d[u] = time
    time += 1

    while len(S) != 0:
        u = S[-1]

        if len(adj_list[u]) != 0:
            v = adj_list[u].popleft()

            if color[v] == "W":
                color[v] = "G"
                d[v] = time
                time += 1
                S.append(v)
        else:
            S.pop()
            color[u] = "B"
            f[u] = time
            time += 1

def Main():
    
    N = int(input())
    adj_list = [deque() for n in range(N)]
    d = [0] * N
    f = [0] * N
    color = [ "W" for i in range(len(d)) ]

    for n in range(N):
        u, k, *V = map(int, input().split())

        if k > 0:
            for i in V:
                adj_list[n].append(i - 1)

    while(True):

        ind = None
        for i in range(N):
            if color[i] == "W":
                ind = i
                break

        if ind == None:
            break
        else:
            dfs(adj_list, d, f, color, ind)

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

Main()

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
input:
6
1 2 2 3
2 2 3 4
3 1 5
4 1 6
5 1 6
6 0

output:
1 1 12
2 2 11
3 3 8
4 9 10
5 4 7
6 5 6
"""
import sys

UNVISITED, VISITED_IN_STACK, POPPED_OUT = 0, 1, 2


def generate_adj_matrix(v_info):
    for v_detail in v_info:
        v_index, adj_num, *adj_list = map(int, v_detail)
        # assert len(adj_list) == adj_num
        init_adj_table[v_index].extend(sorted(adj_list, reverse=True))
    return init_adj_table


def graph_dfs(v_init):
    global time

    # init the first node of overall graph iterations(times >= 1)
    stack.append(v_init)
    d_time[v_init] += time
    # init end

    while stack:
        current = stack[-1]
        v_table = adj_table[current]
        color[current]=VISITED_IN_STACK
        # if adj is None, current's adj(s) have been all visited
        adj = v_table.pop() if v_table else None

        if adj:
            if color[adj] is UNVISITED:
                color[adj] = VISITED_IN_STACK
                time += 1
                d_time[adj] += time
                stack.append(adj)
        else:
            stack.pop()
            color[current] = POPPED_OUT
            time += 1
            f_time[current] += time

    return None


def dfs_start():
    global time
    for i in range(vertices):
        if color[i + 1] == UNVISITED:
            # print('round: ', i + 1)
            graph_dfs(i + 1)
            time += 1


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    vertices = int(_input[0])
    v_info = map(lambda x: x.split(), _input[1:])
    init_adj_table = tuple([] for _ in range(vertices + 1))
    # assert len(vertex_info) == vertex_num

    # config length = (vertex_num + 1)
    stack = []
    color = [UNVISITED] * (vertices + 1)
    d_time, f_time = ([0] * (vertices + 1) for _ in range(2))

    adj_table = generate_adj_matrix(v_info)
    # timing start from 1
    time = 1
    dfs_start()

    for index, v in enumerate(zip(d_time[1:], f_time[1:]), 1):
        print(index, *v)

Python: n=int(input())
D=[0]*(n+1)
F=[0]*(n+1)
v=[[] for i in range(n+1)]
flg=True
t=1
for i in range(n):
  a=list(map(int,input().split()))
  v[a[0]]=sorted(a[2:])

def dfs(p):
  global t
  if D[p]!=0: return
  D[p]=t
  t+=1
  for i in v[p]:
    if D[i]==0: dfs(i)
  F[p]=t
  t+=1

while flg:
  flg=False
  for i in range(1,n+1):
    if D[i]==0:
      flg=True
      dfs(i)

for i in range(1,n+1):
  print(f'{i} {D[i]} {F[i]}')