Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

type TimeRecord struct {
	discoverTime int
	finishTime   int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	timeRecordMap := make([]TimeRecord, n)
	childrenMap := make([][]int, n)
	for i := 1; i <= n; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		timeRecordMap[node-1] = TimeRecord{-1, -1}

		childNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		childrenMap[node-1] = make([]int, childNum)
		for j := 0; j < childNum; j++ {
			child, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			childrenMap[node-1][j] = child
		}
	}

	timer := 1
	for {
		startNode := findStartNode(childrenMap, timeRecordMap)
		if startNode > 0 {
			visit(startNode, &timer, childrenMap, timeRecordMap)
		} else {
			break
		}
	}
	for k, v := range timeRecordMap {
		fmt.Printf("%d %d %d\n", k+1, v.discoverTime, v.finishTime)
	}
}

func findStartNode(childrenMap [][]int, timeRecordMap []TimeRecord) int {
	x := -1
	for node, timeRecord := range timeRecordMap {
		if timeRecord.discoverTime < 0 {
			x = node + 1
			break
		}
	}
	if x < 0 {
		return -1
	}

	found := false
	i := 0
	for i < len(childrenMap) {
		children := childrenMap[i]
		for j := 0; j < len(children); j++ {
			if children[j] == x {
				x = j + 1
				found = true
				break
			}
		}
		if found {
			i = 0
		} else {
			i++
		}
	}
	return x
}

func visit(currentNode int, timer *int, childrenMap [][]int, timeRecordMap []TimeRecord) {
	if timeRecordMap[currentNode-1].discoverTime > 0 {
		return
	}
	children := childrenMap[currentNode-1]
	timeRecordMap[currentNode-1] = TimeRecord{*timer, timeRecordMap[currentNode-1].finishTime}
	(*timer)++
	for i := 0; i < len(children); i++ {
		visit(children[i], timer, childrenMap, timeRecordMap)
	}
	timeRecordMap[currentNode-1] = TimeRecord{timeRecordMap[currentNode-1].discoverTime, *timer}
	(*timer)++
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

Python: n = int(input())

class Node:
    def __init__(self, idd, neighbors):
        self.idd = idd
        self.neighbors = neighbors
        self.foundAt = 0
        self.completeAt = 0
        
    def __repr__(self):
        return "{0} {1} {2}".format(self.idd, self.foundAt, self.completeAt)

Nodes = [None] * n
for i in range(n):
    row = [int(tt) for tt in input().split()]
    Nodes[row[0]-1] = Node(row[0], [ row[j + 2] for j in range(row[1])])
        
def depthSearch(Nodes):
    stack = [Nodes[0]]
    
    time = 2
    current = stack[-1]
    current.foundAt = 1
    while len(stack) > 0 or any([node.foundAt==0 for node in Nodes]):
        if(len(stack)==0):
            newStart = [node for node in Nodes if node.foundAt==0][0]
            newStart.foundAt = time
            stack.append(newStart)
            time += 1
        current = stack[-1]
        if(len(current.neighbors) > 0):
            next_n = Nodes[current.neighbors.pop(0)-1]
            if(next_n.foundAt != 0):
                continue
            next_n.foundAt = time
            stack.append(next_n)
        else:
            current.completeAt = time
            stack.pop(-1)
        time += 1
    return Nodes
Nodes = depthSearch(Nodes)
for node in Nodes:
    print(node)

Python: 
n=int(input())
used=[False for i in range(n)]
d=[0 for i in range(n)]
f=[0 for i in range(n)]
mat=[]
for i in range(n):
    tmp=list(map(int,input().split()))
    mat.append(tmp[2:])

t=1
def dfs(now):
    global t
    if used[now]:
        return
    else:
        used[now]=True
    d[now]=t
    t+=1
    for i in range(len(mat[now])):
        dfs(mat[now][i]-1)
    f[now]=t
    t+=1

for i in range(n):
    if used[i]==False:
        dfs(i)
for i in range(n):
    print(i+1,d[i],f[i])

Python: # -*- coding: utf-8 -*-
N = int(input())
adj = [[0]*N for _ in range(N)]
searched = {n: 0 for n in range(N)}
edge = {}

def find_all(list_, x, j=-1):
    return [i for i, n in enumerate(list_) if n==1 and n != j]


for n in range(N):
    inp = list(map(int, input().split()))
    edge[n] = inp[1]
    for i in inp[2:]:
        adj[inp[0]-1][i-1] = 1

time = 1
stack = []
unsearch = set(range(N))
uncomplete = set(range(N))
result = {n:{"found": 0, "finish": 0} for n in range(N)}

while len(unsearch) > 0 or len(stack) > 0:
    if len(stack) == 0:
        i = min(unsearch)
        result[i]["found"] = time
        unsearch.remove(i)
        time += 1

    
    while True:
        j = i
        for n in sorted(unsearch):
            if adj[i][n] == 1:
                j = n
                result[n]["found"] = time
                unsearch.remove(n)
                stack.append(i)
                time += 1
                break

        if i == j:
            result[i]["finish"] = time
    
            if len(stack) != 0:                
                i = stack.pop()
                time += 1
            else:
                break
        else:
            i = j
                
for n in range(N):
    print("{} {} {}".format(n, result[n]["found"], result[n]["finish"]))

Python: n = int(input())
g = [None] * n
visited = [0] * n
root = set(range(n))
ts = [[0, 0] for _ in range(n)]
t = 1

while n:
    l = list(map(int, input().split()))
    connected = [i - 1 for i in l[2:]]
    g[l[0] - 1] = [i - 1 for i in l[2:]]
    root -= set(connected)
    n -= 1


def dfs(i):
    global g, t, ts, visited
    lts = ts[i]
    lts[0] = t
    visited[i] = 1
    for c in g[i]:
        if not visited[c]:
            t += 1
            dfs(c)
    t += 1
    lts[1] = t


for r in sorted(root):
    dfs(r)

for i, v in enumerate(ts):
    print(i + 1, *v)

Python: #16D8101014F KurumeRyunosuke 2018/6/20

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

"""
for i in range(n):
    for j in range(n):
        if(j!=n-1):
            print(int(ls[i][j]), end=' ')
        else:
            print(int(ls[i][j]))
"""
stuck=[0]
count=1
d=[0 for i in range(n)]
f=[0 for i in range(n)]
d[0]=count
while True:
	count+=1
	p=0
	for i in range(n):
		if ls[stuck[len(stuck)-1]][i] is not 0:
			ls[stuck[len(stuck)-1]][i]=0
			
			p=1
			#print(stuck)
			stuck.append(i)
			d[stuck[len(stuck)-1]]=count
			break
	if p is 1:
		for i in range(n):
			ls[i][stuck[len(stuck)-1]]=0

	if p is 0:
		#print("//")
		a=stuck.pop()
		f[a]=count
		for i in range(n):
			ls[a][i]=0

	if len(stuck) is 0:
		#print("break")
		break

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

Python: #!/usr/bin/env python
# -*- coding:utf-8 -*-
from __future__ import division,print_function
import time
import sys
import io
import re
import math
start = time.clock()
i = 0
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(sys.stdin.readline())
    L=[]
    for _ in range(num):
        L.append([int(s) for s in sys.stdin.readline().split()[2:]])
    d=[0]*num
    f=[0]*num
    tm=0
    for i in range(num):
        if not d[i]:
            tm=walk(i,tm,L,d,f)
    for i in range(num):
        print(i+1,d[i],f[i])
 
main()

Python: n = int(input())
A = [[0 for i in range(n)] for j in range(n)]

for i in range(n):
    u, k, *v = list(map(int, input().split()))
    for j in v:
        A[int(u)-1][int(j)-1] = 1
        A[int(j)-1][int(u)-1] = 1

# for row in A:
#     msg = ' '.join(map(str, row))
#     # print(msg)

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

t = 0
d[0] = t

# recursive


def dfs(u):
    global t
    # print('visit:', str(u), str(t))
    t += 1
    d[u] = t
    for i in range(len(A[u])):
        if A[u][i] == 1 and d[i] == -1:
            dfs(i)
    t += 1
    f[u] = t
            

dfs(0)


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