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

func dfs(currentId vertexId, timestamp int, vertices []vertex) int {
	currentVertex := &vertices[currentId-1]
	if currentVertex.isVisited() {
		return timestamp
	}
	timestamp = timestamp + 1
	currentVertex.firstVisitAt = timestamp
	for _, adjId := range currentVertex.adjs {
		timestamp = dfs(adjId, timestamp, vertices)
	}
	timestamp = timestamp + 1
	currentVertex.finishVisitAt = timestamp
	return timestamp
}

func solveDfs(vertices []vertex) {
	timestamp := 0
	for {
		vid := vertexId(-1)
		for i := 0; i < len(vertices); i++ {
			if !vertices[i].isVisited() {
				vid = vertexId(i+1)
				break
			}
		}
		if vid > 0 {
			timestamp = dfs(vid, timestamp, vertices)
		} else {
			break
		}
	}
}

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)
	}

	solveDfs(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: n = int(input())
a = [[0]*n for i in range(n)]
  
for i in range(n):
    v = list(map(int, input().split()))
    u = v[0]
    k = v[1]
    for j in range(k):
        a[u - 1][v[2 + j] - 1] = 1

d = [0] * n
f = [0] * n
isDiscovered = [False] * n
time_stamp = 0

def dfs(x):
    global time_stamp
    isDiscovered [x] = True
    time_stamp = time_stamp + 1
    d[x] = time_stamp
    for i in range(n):
        if a[x][i] == 1 and isDiscovered[i] == False:
            dfs(i)
    time_stamp = time_stamp + 1
    f[x] = time_stamp

for i in range(n):
    if isDiscovered[i] == False:
        dfs(i)

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

Python: #連結グラフではない
n = int(input())
V = [[] for _ in range(n+1)]
for _ in range(n):
    inpt = list(map(int,input().split( )))
    if len(inpt)>2:
        V[inpt[0]] = inpt[2:]


D = [0]*(n+1)
F = [0]*(n+1)

time = 1
Q = [1]
D[0] = -1
D[1] = 1
while len(Q) > 0 or 0 in D[1:]:
    v = Q[-1]
    remains = False
    for i in V[v]:
        if D[i] == 0:
            D[i] = time+1
            Q.append(i)
            remains = True
            break
    if not remains:
        F[v] = time+1
        Q.pop()
        
    time += 1
    if len(Q) == 0:
        if 0 in D:
            time += 1
            nxt = D.index(0)
            Q.append(nxt)
            D[nxt] = time
        else:
            pass
        

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

Python: from sys import setrecursionlimit

setrecursionlimit(10 ** 9)

n = int(input())

graph = []

for _ in range(n):
    tmp = list(map(int, input().split()))

    if tmp[1] == 0:
        graph.append([])
        continue
    else:
        graph.append(list(map(lambda x: x - 1, tmp[2: tmp[1] + 2])))

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

time = 1


def dfs(x):
    if d[x] != -1:
        return

    global time

    d[x] = time
    time += 1

    for n in graph[x]:
        dfs(n)

    f[x] = time
    time += 1


for i in range(n):
    dfs(i)

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

Python: n = int(input())
A = [[0 for j in range(n)] for i in range(n)]
for i in range(n):
    arr = list(map(int, input().split(' ')))
    u, k, v = arr[0], arr[1], arr[2:]
    for j in range(k):
        A[u-1][v[j]-1] = 1

hist_stack = [0]
time_hist = [0]

vert_hist = [[] for i in range(n)]
vert_hist[0].append(1)
time = 2
while True:
    flag = False
    if len(hist_stack) == 0: break
    for j in range(n):
        if A[hist_stack[-1]][j] == 1 and j not in time_hist:
            hist_stack.append(j)
            time_hist.append(j)
            vert_hist[j].append(time)
            flag = True
            break
    if not flag:
        j = hist_stack.pop()
        time_hist.append(j)
        vert_hist[j].append(time)
    time += 1

for i in range(n):
    print(i+1, ' '.join(list(map(str, vert_hist[i]))))

Python: #coding:utf-8

n = int(input())
c = ["white" for i in range(n)]
d = [0 for i in range(n)]
f = [0 for i in range(n)]
S = []
class DFS:
    def __init__(self, key, color="white",nex=None):
        self.color = color
        self.nex = nex
        self.key = key

objList = [DFS(i+1) for i in range(n)]
for i in range(n):
    data = list(map(int,input().split()))
    times = data[1]
    obj = objList[i]
    for j in range(times):
        index = data[2+j] - 1
        nextobj = DFS(index+1)
        obj.nex = nextobj
        obj = obj.nex

S.append(1)
obj = objList[0]
obj.color = "gray"
d[0] = 1
f[0] = 1
c[0] = "gray"

time = 1
while S != []:
    index = S[-1] - 1
    u = objList[index]
    v = u.nex

    time += 1
    if v != None and c[v.key - 1] == "white":
        objList[index] = v
        index = v.key - 1
        v = objList[index]
        c[v.key-1] = "gray"
        d[index] = time
        S.append(v.key)
        
    else:
        S.pop()
        c[u.key-1] = "black"
        f[index] = time

k = 1
for i,j in zip(d,f):
    print(k,i,j)
    k += 1

Python: N = int(input())

E = [None] * (N+1)
for _ in range(N):
    u, k, *vs = list(map(int, input().split()))
    E[u] = vs

d = [0] * (N+1)
f = [0] * (N+1)
t = 0

def dfs(v):
    global t, d, f
    if d[v]:
        return
    t += 1
    d[v] = t
    for u in E[v]:
        dfs(u)
    t += 1
    f[v] = t

for v in range(1, N+1):
    dfs(v)

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

Python: n = int(input())

adj = [None]
for i in range(n):
    adj_i = list(map(int, input().split()[2:]))
    adj.append(adj_i)

# searched or not, number of vertex, discovery time and finishing time.
sndf = [None]
for i in range(1, n + 1):
    sndf.append([False, i])

path = []

time = 0

def dfs(u):
    global time
    sndf[u][0] = True
    time += 1
    sndf[u].append(time)

    for v in adj[u]:
        if not sndf[v][0]:
            dfs(v)
    sndf[u][0] = True
    time += 1
    sndf[u].append(time)


for i in range(1, n + 1):
    if not sndf[i][0]:
        dfs(i)

for x in sndf[1:]:
    print(*x[1:])