Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	f         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes] = &DirectedGraphNode{}
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].f = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

var time = 0

func fillDistancesByDepthFirstSearch(g *DirectedGraph) {
	for _, u := range g.nodes[1:] {
		if !u.visited {
			dfsVisit(g, u)
		}
	}
}

func dfsVisit(g *DirectedGraph, u *DirectedGraphNode) {
	time++
	u.d = time

	u.visited = true
	for _, v := range u.adjacents {
		if !v.visited {
			v.parent = u
			dfsVisit(g, v)
		}
	}
	time++
	u.f = time
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	fillDistancesByDepthFirstSearch(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		fmt.Println(node.key, node.d, node.f)
	}
}

Python: """Depth First Search."""

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 = []

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

    while path:
        u = path[-1]
        if adj[u]:
            v = adj[u].pop(0)
            if not sndf[v][0]:
                time += 1
                sndf[v].append(time)
                path.append(v)
        else:
            path.pop()
            sndf[u][0] = True
            time += 1
            sndf[u].append(time)


dfs(1)

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

Python: import sys

n = int(sys.stdin.readline())+1

m = [[0] * n for _ in range(n)]
discover_time = [-1] * n
finish_time = [0] * n
clock = -1

def walk(p):
    global clock
    clock += 1

    for i in range(n):
        if m[p][i]==0: continue
        if discover_time[i]<0:
            discover_time[i] = clock
            clock = walk(i)
            finish_time[i] = clock
            clock +=1

    return clock

m[0] = [1] * n
for i in range(1,n):
    cols = list(map(int, sys.stdin.readline().split()))
    for j in cols[2:]:
        m[i][j]=1

walk(0)

for i in range(1,n):
    print(i,discover_time[i],finish_time[i])

Python: 
# ??±???????????¢?´¢(Depth First Search)

def DFS(n = 1, A = [0], i = 0, d = [0], f = [0], time = 1):
    for j in range(n):
        if A[i][j] == 1 and d[j] == 0:
            time = time + 1
            d[j] = time
            time = DFS(n, A, j, d, f, time)
    time = time + 1
    f[i] = time
    return time

n = int(raw_input())
A = [0] * n
for i in range(n):
    A[i] = [0] * n

for i in range(n):
    value = map(int, raw_input().split())
    u = value[0] - 1
    k = value[1]
    nodes = value[2:]
    for i in range(k):
        v = nodes[i] - 1
        A[u][v] = 1

d = [0] * n
f = [0] * n

time = 0
for i in range(n):
    if d[i] == 0:
        time = time + 1
        d[i] = time
        time = DFS(n, A, i, d, f, time)

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

Python: T = [0]

def curserch(N,k,T,P,n):
    T[0] = T[0]+1
    P[k]["d"] = T[0]
    for i in range(1,n+1):
        if N[k][i]==1 and P[i]["d"]==0:
            curserch(N,i,T,P,n)
            T[0] = T[0]+1
            P[i]["f"]=T[0]


n = int(input())
A = [[0 for j in range(n+1)] for i in range(n+1)]


for i in range(n):
    vec = input().split()
    u = int(vec[0])
    k = int(vec[1])
    nodes = vec[2:]
    for i in range(int(k)):
        v = int(nodes[i])
        A[u][v] = 1

P=[{"d":0} for i in range(n+1)]
for i in range(1,n+1):
    if P[i]["d"]==0:
        curserch(A,i,T,P,n)
        T[0] = T[0]+1
        P[i]["f"]=T[0]
for i in range(1,n+1):
    print(i,P[i]["d"],P[i]["f"])

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:
		t=0
		for i in range(n):
			for j in range(n):
				if ls[i][j] is not 0 and t is 0:
					count+=1
					stuck.append(i)
					d[stuck[len(stuck)-1]]=count
					#print(i)
					t=1
					
		if t is 0:
			break
		#print("break")

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

Python: n=0
t=1
def adjacent_matrix():
    global n
    n=int(input())
    v=[]
    array=[]
    for i in range(n):
        zero=[0 for i in range(n)]
        a=list(map(int,input().split()))
        a=a[2:]
        for j in a:
            zero[j-1]=1
        array.append(zero)
    return array
def dfs(array,i,d,f):
    global t
    if i == n:
        return
    else:
        if(d[i] == 0):
            d[i] = t
            t += 1
            for (j,x) in enumerate(array[i]):
                if x == 1:
                    dfs(array,j,d,f)
            f[i] = t
            t += 1
    return 


def main():
    array=adjacent_matrix()
    print()
    d=[0 for i in range(n)]
    f=[0 for i in range(n)]
    for i in range(n):
        dfs(array,i,d,f)
    for i in range(n):
        print("{} {} {}".format(i+1,d[i],f[i]))

if __name__ == "__main__":
    main()