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: import sys
import itertools
# import numpy as np
import time
import math
 
sys.setrecursionlimit(10 ** 7)
 
from collections import defaultdict
 
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N = int(input())

adj = [[] for _ in range(N)]

for i in range(N):
    line = list(map(int, input().split()))
    u = line[0] - 1
    if line[1] == 0:
        continue
    vs = line[2:]
    for v in vs:
        adj[u].append(v - 1)

d = [-1] * N
f = [-1] * N

def dfs(v, t):
    d[v] = t
    nx = t + 1
    for u in adj[v]:
        if d[u] > -1:
            continue
        nx = dfs(u, nx)
    f[v] = nx
    return f[v] + 1

nx = 1
for i in range(N):
    if d[i] > - 1:
        continue
    nx = dfs(i, nx)

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

Python: #!/usr/bin/env python
from __future__ import division, print_function
from sys import stdin


def walk(index, tm, L, d, f):
    tm += 1
    d[index] = tm
    for i in L[index]:
        if not d[i-1]:
            tm = walk(i-1, tm, L, d, f)
    tm += 1
    f[index] = tm
    return tm


def main():
    num = int(stdin.readline())

    L = []
    for _ in xrange(num):
        L.append([int(s) for s in stdin.readline().split()[2:]])

    d = [0] * num
    f = [0] * num
    tm = 0
    for i in xrange(num):
        if not d[i]:
            tm = walk(i, tm, L, d, f)

    for i in xrange(num):
        print(i+1, d[i], f[i])


main()

Python: n = int(input())
G = [[] for _ in range(n)]
u1 = 0
for _ in range(n):
    u, k, *v = [int(i) for i in input().split()]
    G[u - 1] = v
    if k != 0 and u1 == 0:
        u1 = u

time = 1
u = u1
D = []
F = []
out = [[i+1, 0, 0] for i in range(n)]
T = []
while True:
    if u not in D:
        out[u - 1][1] = time
        D.append(u)
        T.append(u)

    for f in F:
        if f in G[u - 1]:
            idx = G[u - 1].index(f)
            del G[u - 1][idx]

    if G[u - 1] == []:
        time += 1
        out[T.pop() - 1][2] = time
        F.append(u)
        if T == []:
            if len(D) == n:
                break
            else:
                for ni in range(n):
                    if ni + 1 not in D:
                        u = ni + 1
                        break
                time += 1
                continue
        else:
            u = T[-1]
    else:
        if G[u - 1][0] not in D:
            time += 1
        u = G[u - 1].pop(0)

for ni in range(n):
    print(*out[ni])

Python: class Vertex:
    _id = -1
    _children = []
    _visited = False
    _visited_time = 0
    _all_visited_time = 0

    def __init__(self, i, c):
        self._id = i
        self._children = c

    def getId(self):
        return self._id

    def getChildren(self):
        return self._children

    def isVisited(self):
        return self._visited

    def getVisitedTime(self):
        return self._visited_time

    def setVisitedTime(self, t):
        self._visited_time = t
        self._visited = True

    def getAllVisitedTime(self):
        return self._all_visited_time

    def setAllVisitedTime(self, t):
        self._all_visited_time = t

    def print(self):
        print("{} {} {}".format(self._id, self._visited_time, self._all_visited_time))


n = int(input())
graph = [0 for i in range(n)]
time = 0

# 頂点登録
for i in range(n):
    u = list(map(int, input().split(' ')))
    adj = []
    if u[1] > 0:
        adj = u[2:u[1]+2]
    graph[u[0]-1] = Vertex(u[0], adj)

# DFS
def dfs(v):
    global time
    time += 1
    v.setVisitedTime(time)
    for child in v.getChildren():
        if not graph[child-1].isVisited():
            dfs(graph[child-1])
    time += 1
    v.setAllVisitedTime(time)

# DFS実行
for v in graph:
    if not v.isVisited():
        dfs(v)

# 回答を出力
for v in graph:
    v.print()

Python: from collections import deque


def conv_list(n):
    adj_matrix = []
    for _ in range(n):
        adj_list = input().split()
        adj_list = list(map(int, adj_list))
        adj_row = [False] * n
        if adj_list[1] > 0:
            for i in adj_list[2:]:
                adj_row[i - 1] = True
        adj_matrix.append(adj_row)
    return adj_matrix


def depth_first_search(adj_matrix, n):
    visited = [None] * n
    count = 1
    searched = [None] * n
    start = 0
    stack = deque()
    stack.append(start)
    visited[start] = 1
    while count <= 2 * n:
        has_edge = adj_matrix[start]
        i = 0
        while i < n:
            if has_edge[i] and visited[i] is None:
                stack.append(i)
                count += 1
                visited[i] = count
                break
            i += 1
        if i < n:
            start = i
        else:
            searched_node = stack.pop()
            count += 1
            searched[searched_node] = count
            if len(stack) > 0:
                start = stack[-1]
            elif count < 2 * n:
                start = visited.index(None)
                stack.append(start)
                count += 1
                visited[start] = count
            else:
                break
    return visited, searched


def main():
    n = int(input())
    adj_matrix = conv_list(n)
    visited, searched = depth_first_search(adj_matrix, n)
    for i in range(n):
        print("{} {} {}".format(i + 1, visited[i], searched[i]))


if __name__ == "__main__":
    main()