Go: package main

/*
深さ優先探索
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		ints := eGetInts(scanner)
		num, vcount := ints[0], ints[1]
		g[i] = make([]int, vcount)
		for j := 0; j < vcount; j++ {
			g[num][j] = ints[j+2]
		}
	}
	hist := make([]struct{ d, f int }, n+1)
	t := 0
	var visit func(int)
	visit = func(num int) {
		if hist[num].d == 0 {
			stack := []int{}
			t++
			hist[num].d = t
			stack = append(stack, num)
			for len(stack) > 0 {
				// トップを訪問する
				top := stack[len(stack)-1]
				for i := 0; i < len(g[top]); i++ {
					if hist[g[top][i]].d == 0 {
						t++
						hist[g[top][i]].d = t
						stack = append(stack, g[top][i])
						goto endloop
					}
				}
				// 訪問場所がなくなったら
				// pop
				stack = stack[0 : len(stack)-1]
				t++
				hist[top].f = t
			endloop:
			}
		}
	}
	for i := 1; i < n+1; i++ {
		visit(i)
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, hist[i].d, hist[i].f)
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

Python: import sys
# sys.stdin = open('input.txt')

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

def dfs(u):
    global time
    status[u] = VISITING
    time += 1
    discoverTime[u] = time
    for v in range(n):
        if matrix[u][v] and status[v] == NOT_VISITED:
            dfs(v)
    status[u] = VISITED
    time += 1
    finishTime[u] = time


n = int(input())
matrix = [[0]*n for i in range(n)]
time = 0
discoverTime = [0] * n
finishTime = [0] * n

NOT_VISITED = 0 # WHITE
VISITING = 1 # GRAY
VISITED = 2 # BLACK
status = [NOT_VISITED] * n

fillMatrix()
# Calling dfs(0) alone cannot reach nodes not connected from 0
for i in range(n):
    if status[i] != VISITED:
        dfs(i)

for i in range(n):
    ans = []
    ans.append(i+1)
    ans.append(discoverTime[i])
    ans.append(finishTime[i])
    ans = map(str, ans)
    print(' '.join(ans))

Python: # -*- coding: utf-8 -*-


class Graph:
    def __init__(self, n, adj_matrix):
        self.n = n
        self.g = adj_matrix

    def show(self):
        for _ in self.g:
            print(*_)

    def dfs(self, u, init=False):
        if init:
            self.states = [1] * self.n
            self.stack = []
            self.d = [None] * self.n
            self.f = [None] * self.n
            self.time = 0

        self.states[u] = 0
        self.time += 1
        self.d[u] = self.time

        for v, edge in enumerate(self.g[u]):
            if edge and self.states[v]:
                self.dfs(v)

        self.states[u] = 0
        self.time += 1
        self.f[u] = self.time

    def show_dfs(self, start=0):
        self.dfs(u=start, init=True)
        for i, (d, f) in enumerate(zip(self.d, self.f)):
            print(i + 1, d, f)


if __name__ == '__main__':
    n = int(input())
    adj_matrix = [[0] * n for i in range(n)]
    for i in range(n):
        for v in input().split()[2:]:
            adj_matrix[i][int(v) - 1] = 1

    g = Graph(n, adj_matrix)
    g.show_dfs()

Python: time = 1

class Vertex:
	def __init__(self, u, k):
		self.u = u
		self.vertices = [0] * k
		self.d = self.f = 0
	def __str__(self):
		return str(self.u) + ' ' + str(self.d) + ' ' + str(self.f)

def DFS(n, vertices):
	for i in range(n):
		if vertices[i].d == 0:
			DFS_(vertices, vertices[i].u)
			
def DFS_(vertitces, u):
	vertex = vertices[u-1]
	if vertex.d == 0:
		global time
		vertex.d = time
		time += 1
		for i in range(len(vertex.vertices)):
			DFS_(vertices, vertex.vertices[i])
		vertex.f = time
		time += 1
	
n = int(input())
vertices = []
for i in range(n):
	v = list(map(int, input().split()))
	u = v[0]
	k = v[1]
	vertex = Vertex(u, k)
	for j in range(k):
		vertex.vertices[j] = v[j+2]
	vertices.append(vertex)

DFS(n, vertices)
for i in range(n):
	print(str(vertices[i]))

Python: n = int(input())
l = [[] for i in range(n)]


class V:
    def __init__(self, node):
        self.d = -1
        self.f = -1
        self.node = node


for i in range(n):
    _input = [int(j) - 1 for j in input().split(" ")]
    u = _input[0]
    k = _input[1] + 1
    node = sorted(_input[2::])
    if u in node:
        node.remove(u)
    l[u] = V(node)

time = 1


def DFS(i):
    global time
    if l[i].d == -1:
        l[i].d = time
    time += 1
    for n in l[i].node:
        if l[n].d == -1:
            DFS(n)
            time+=1
    if l[i].f == -1:
        l[i].f = time
    return


for i in range(n):
    if l[i].d == -1:
        DFS(i)
        time+=1

for i, v in enumerate(l):
    print(i + 1, v.d, v.f)

Python: n = int(input())
g = [[] for i in range(n)]
for i in range(n):
    g[i] = list(map(lambda x:int(x)-1,input().split()))[2:]

def dfs(v,t):
    t += 1
    d[v] = t
    for i in g[v]:
        if d[i]==-1:
            t = dfs(i,t)
    t += 1
    f[v] = t
    return t

t = 0
d = [-1]*n
f = [-1]*n

for i in range(n):
    if d[i]==-1:
        t = dfs(i,t)

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

Python: N = input()
color = [0] * N
d = [0] * N
f = [0] * N
nt = [0] * N
m = [[0] * N for i in range(N)]
S = []
tt = 0

def next(u):
    w = nt[u]
    for v in range(w, N):
        nt[u] = v + 1
        if( m[u][v] ):
            return v
    return -1

def dfs_visit(r):
    global tt 
    S.append(r)
    tt += 1
    d[r] = tt

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

        v = next(u)
        if ( v != -1 ):
            if ( color[v] == 0 ):
                color[v] = 1
                tt += 1
                d[v] = tt
                S.append(v)
        else:
            S.pop()
            color[u] = 2
            tt += 1
            f[u] = tt

def dfs():
    for u in range(N):
        if( color[i] == 0 ):
            dfs_visit(u)

if __name__ == '__main__':

    for i in range(N):
        v = map(int, raw_input().split())
        for j in v[2:]:
            m[i][j-1] = 1
    
    dfs()

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