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
	startNode := 1
	for {
		visit(startNode, &timer, childrenMap, timeRecordMap)
		startNode = findStartNode(childrenMap, timeRecordMap)
		if startNode < 0 {
			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
		}
	}
	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: # -*- 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]

Python: import sys
input = lambda: sys.stdin.readline().rstrip() 
import bisect as bs

def resolve():
    n = int(input())
    ukv = [list(map(int, input().split())) for _ in range(n)]

    d = [-1]*n
    f = [-1]*n
    stk = []
    status = [0]*n

    t = 1
    for i in range(n):
        if status[i]==0:
            stk.append(i)
            while len(stk)>0:
                a = stk[-1]
                if status[a]==0:
                    d[a] = t
                    t += 1
                    status[a] = 1
                elif status[a]==1:
                    stk.pop()
                    f[a] = t
                    t += 1
                    status[a] = 2
                else:
                    stk.pop()
                for i in reversed(ukv[a][2:]):
                    if status[i-1]==0:
                        stk.append(i-1) 

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

if __name__ == '__main__':
    resolve()

Python: n = int(input())
graph = [list(map(int, input().split())) for i in range(n)]

v_color = ["WHITE"] * (n+1) # WHITE:????¨???????GRAY:?¨??????????BLACK:??¢?´¢??????
d = [0] * (n+1)
f = [0] * (n+1)
stack = []

def DFS(u):
    time = 0
    stack.append(u)
    
    while stack != []:
        u = stack[-1]
        time += 1
        
        v_color[u] = "GRAY"
        if d[u] == 0:
            d[u] = time
        
        for Next in graph[u-1][2:]:
            if v_color[Next] == "WHITE":
                stack.append(Next)
                break
        
        else:
            v_color[u] = "BLACK"
            f[u] = time +1
            stack.pop()
        
DFS(1)
    
for i in range(1,n+1):
    print(i,d[i],f[i])