Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	firstVisitAt int
	finishVisitAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		firstVisitAt: 0,
		finishVisitAt: 0,
		adjs: adjs,
	}
}

func (v *vertex) doesAllAdjsVisited(vertices []vertex) bool {
	for _, vId := range v.adjs {
		adj := vertices[vId-1]
		if !adj.isVisited() {
			return false
		}
	}
	return true
}

func (v *vertex) isFirstVisit() bool {
	return v.firstVisitAt == 0
}

func (v *vertex) isVisited() bool {
	return v.firstVisitAt > 0
}

func (v *vertex) nextVertex(vertices []vertex) (vertexId, error) {
	for _, vId := range v.adjs {
		adj := vertices[vId-1]
		if !adj.isVisited() {
			return vId, nil
		}
	}
	return vertexId(-1), fmt.Errorf("illegal")
}

func dfs(currentId vertexId, timestamp int, vertices []vertex) int {
	timestamp = timestamp + 1
	currentVertex := &vertices[currentId-1]
	if currentVertex.isFirstVisit() {
		currentVertex.firstVisitAt = timestamp
	}
	for !currentVertex.doesAllAdjsVisited(vertices) {
		nextVertexId, _ := currentVertex.nextVertex(vertices)
		timestamp = dfs(nextVertexId, timestamp, vertices)
	}
	timestamp = timestamp + 1
	currentVertex.finishVisitAt = timestamp
	return timestamp
}

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

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

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	dfs(vertexId(1), 0, vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", vertices[i].id, vertices[i].firstVisitAt, vertices[i].finishVisitAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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

Python: import sys
u=[]
k=[]
v=[]

time = 0

n=int(sys.stdin.readline().strip())
yattayatu=[False for i in range(n)]

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

for i in range(n):
	inp = sys.stdin.readline().strip().split(" ")
	inp = list(map(lambda x: int(x), inp))
	u.append(inp[0])
	k.append(inp[1])
	v.append(inp[2:])


def func(nodeid):
	global time
	if(yattayatu[nodeid-1]==True):
		return
	time += 1
	s[nodeid-1] = time
	for i in range(k[nodeid-1]):
		func(v[nodeid-1][i])
	time +=1
	f[nodeid-1]=time
	yattayatu[nodeid-1]=True

func(1)

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

Python: def dfs(G, u, t, d, visited):
  found = t
  visited.add(u)
  t += 1
  for v in G[u]:
    if v not in visited:
      t = dfs(G, v, t, d, visited)
  complete = t
  d[u] = (found, complete)
  t+=1
  return t


n = int(input())
G = {}
for _ in range(n):
  entries = list(map(int, input().split(' ')))
  u = entries[0]
  k = entries[1]
  G[u] = set()
  for v in entries[2:]:
    G[u].add(v)


d = {}
dfs(G, 1, 1, d, set())
for i in sorted(d):
  print(i,d[i][0],d[i][1])

Python: n = int(input())
a = []
for i in range(n):
    a += [list(map(int, input().split()))[2:]]
cnt = 1
pre = [0]*n
aft = [0]*n
color = [0]*n
def dfs(s):
    global cnt
    pre[s-1] = cnt
    cnt += 1
    color[s-1] = 1
    for i in a[s-1]:
        if color[i-1] == 0:dfs(i)
    aft[s-1] = cnt
    cnt += 1

for i in range(n):
    if color[i] == 0:
        dfs(i+1)

for i in range(n):
    print(i+1, pre[i], aft[i])

Python: #coding: utf-8

n = int(input())
color = ["white" for i in range(n)]
d = [[] for i in range(n)]
global t
t = 0
M = [[False for i in range(n)] for j in range(n)]
for i in range(n):
    data = list(map(int,input().split()))
    u = data[0]
    k = data[1]
    if i == 0:
        start = u
    for v in data[2:2+k]:
        M[u-1][v-1] = True


def search(u,t):
    t += 1
    color[u-1] = "gray"
    d[u-1].append(t)
    for v in range(1,n+1):
        if M[u-1][v-1] and color[v-1] == "white":
            t = search(v,t)
    color[u-1] = "black"
    t += 1
    d[u-1].append(t)
    return t

t = search(start, t)
for i in range(1,n+1):
    if color[i-1] == "white":
        t = search(i, t)

for i in range(n):
    print(i+1, d[i][0], d[i][1])

Python: def DPS(graph,vertex,dis_time,fin_time,tmp_time):
    dis_time[vertex]=tmp_time[0]
    for i in range(len(graph[0])):
        if(graph[vertex][i] !=0 and dis_time[i]==0):#枝先の頂点が探索済みでなかったら、
            tmp_time[0]+=1
            DPS(graph,i,dis_time,fin_time,tmp_time)
    
    if(dis_time[vertex]==tmp_time[0]):#vertexから、どの頂点に対しても調査が進まなかったら
        tmp_time[0]+=1
    fin_time[vertex]=tmp_time[0]
    tmp_time[0]+=1



#グラフの作成
n=int(input())
graph=[[0]*n for loop in range(n)]
for loop in range(n):
    tmp_ope=list(map(int,input().split()))
    for j in range(tmp_ope[1]):
        graph[tmp_ope[0]-1][tmp_ope[j+2]-1]=1


dis_time=[0]*n
fin_time=[0]*n
tmp_time=[1]
for i in range(n):
    if(dis_time[i]==0):
        DPS(graph,i,dis_time,fin_time,tmp_time)

for i in range(n):
    print(f"{i+1} {dis_time[i]} {fin_time[i]}")

Python: cnt = 1
def dep(G,s_cnt,f_cnt,np):
    global cnt
    s_cnt[np] = cnt
    cnt += 1
    for i in range(n):
        if G[np][i] == 1 and s_cnt[i] == 0:
            dep(G,s_cnt,f_cnt,i)
    f_cnt[np] = cnt
    cnt += 1
    

n = int(input())
G = [[0 for i in range(n)] for j in range(n)]
s_cnt = [0 for i in range(n)]
f_cnt = [0 for i in range(n)]

for i in range(n):
    S = list(map(int, input().split()))
    tmp_n = S[1]
    for j in range(tmp_n):
        G[i][S[j+2]-1] = 1
        
for i in range(n):
    if s_cnt[i]==0:
        dep(G,s_cnt,f_cnt,i)

for i in range(n):
    print(i+1,s_cnt[i],f_cnt[i])

Python: n = int(input())
graph = [[] for _ in range(n)]
for i in range(n):
    in_list = list(map(int, input().split()))
    u = in_list[0]
    graph[u - 1] = in_list[2:]

d = [0 for _ in range(n)]
f = [0 for _ in range(n)]
time = 0


def dfs(now, prev, graph, d, f):
    global time
    time += 1
    d[now] = time
    if not graph[now]:
        f[now] = time + 1
        time += 1
        return
    for k in graph[now]:
        if k - 1 == prev or d[k-1] !=0:
            continue
        dfs(k - 1, now, graph, d, f)
    else:
        time += 1
        f[now] = time
    return d, f


d, f = dfs(0, 0, graph, d, f)
for i in range(1, n + 1):
    print(i, d[i - 1], f[i - 1])

Python: from collections import defaultdict as dd

N = int(input())
graph = dd(list)
seen = dd(int)
u = []
d, f = dd(int), dd(int)
ts = 1
for _ in range(N):
  info = list(map(int, input().split()))
  u.append(info[0])
  graph[info[0]] = info[2:]

def dfs(v):
  global ts
  d[v] = ts
  ts += 1
  
  seen[v] = 1
  for next_v in graph[v]:
    if seen[next_v]:
      continue
    dfs(next_v)
  
  f[v] = ts
  ts += 1

for key in u:
  if seen[key]:
    continue
  dfs(key)

for id in u:
  print("{} {} {}".format(id, d[id], f[id]))

Python: def dfs(v, time_, d, f, dp):
    if d[v] == 0:
        d[v] = time_
    for i in range(len(dp[v])):
        if d[dp[v][i]] == 0:
            time_ = dfs(dp[v][i], time_ + 1, d, f, dp)
    f[v] = time_ + 1
    return time_ +  1


def main():
    N = int(input())
    dp = [[] for i in range(N)]
    for i in range(N):
        line = [int(k) for k in input().split()]
        for j in range(len(line)):
            if j == 0 or j == 1:
                continue
            dp[line[0] - 1].append(line[j] - 1)

    d = [0] * N
    f = [0] * N
    time_ = 1
    for i in range(N):
        if d[i] == 0:
            time_ = dfs(i, time_, d, f, dp)
            time_ += 1
    for i in range(N):
        print(i + 1, d[i], f[i])

if __name__ == '__main__':
    main()