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: from sys import stdin
input = stdin.readline

N = int(input())
WHITE = 0
GRAY = 1
BLACK = 2

M = [[0]*N for _ in range(N)]
color = [WHITE]*N  # colorの初期化は最初に行っておく。
d = [0]*N
f = [0]*N

def dfs_visit(u):
    global tt
    color[u] = GRAY
    tt += 1
    d[u] = tt # 最初の訪問
    for v in range(N):
        if M[u][v] == 0:
            continue
        if color[v] == WHITE:
            dfs_visit(v)
    color[u] = BLACK
    tt += 1
    f[u] = tt # 訪問の完了

def dfs():
    global tt
    tt = 0

    for u in range(N):
        if color[u] == WHITE:
            # 未訪問のuを始点として深さ優先探索
            dfs_visit(u)
    for u in range(N):
        print(str(u+1) + ' ' + str(d[u]) + ' ' + str(f[u]))
for _ in range(N):
    u, k, *vv = input().split()
    u = int(u)-1  # 0オリジンにする
    k = int(k)    # kは使わない
    for v in vv:
        v = int(v)-1
        M[u][v] = 1
dfs()

Python: global t
t = 0

class Node:
    def __init__(self, num, deg, neib):
        self.num = num
        self.deg = deg
        self.neib = neib

def dfs(G, d, f, now): #now:1,2,...
    #print("now:",now)
    global t
    t += 1
    #print("t:",t)
    if d[now-1] != 0:
        t -= 1
        #print("has searched or hit roop")
    else:
        d[now-1] = t
        #print("d:",d)
        #print("f:",f)
        for i in G[now-1].neib:
            #print("i:",i)
            if i != -1:
                #print("next node")
                dfs(G, d, f, i)
            #else: print("end of branch")
        t += 1
        f[now-1] = t

        #print("f:",f)


dnum = int(input()) #頂点数
N = []
for i in range(dnum):
    data = input().split()
    
    u = int(data[0])
    k = int(data[1])
    if k > 0:
        v = list(map(int, data[2:]))
    else:
        v = [-1]

    node = Node(u,k,v)
    N.append(node)

d = [0]*dnum #find time
f = [0]*dnum #finish time

while 0 in d:
    s = d.index(0)
    dfs(N, d, f, s+1)
    #print("looks like finish")

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

Python: class Node(object):
    def __init__(self, V):
        self.V = V
        self.find_time = 0
        self.finish_time = 0
        self.is_finded = False


n = int(input())
nodes = [0] * 100
for i in range(n):
    data = input().split()
    V = list(map(int, data[2:]))
    V.sort(reverse = True)
    nodes[int(data[0])] = Node(V)

find_q = []
find_q.append(1)
cnt = 1
q_size = len(find_q)
while q_size != 0:
    #print(find_q)
    node = nodes[find_q[q_size -1]]

    if node.is_finded == False:
        node.find_time = cnt
        cnt += 1
        node.is_finded = True
        if len(node.V) == 0:
            node.finish_time = cnt
            cnt += 1
            del find_q[q_size -1]
            q_size = len(find_q)
        else:
            for x in node.V:
                if x in find_q:
                    find_q.remove(x)
                if nodes[x].finish_time == 0: 
                    find_q.append(x)
            q_size = len(find_q)

    else:   #node is finded
        node.finish_time = cnt
        cnt += 1
        del find_q[q_size -1]
        q_size = len(find_q)
        continue

for i in range(1, n+1):
    print(i, nodes[i].find_time, nodes[i].finish_time)

Python: def d(u):
 global t
 C[u]=0;D[u]=t;t+=1
 for v in M[u]:
  v=int(v)-1
  if C[v]:d(v)
 F[u]=t;t+=1
N=int(input());R=range(N)
M=[input().split()[2:]for _ in R]
C,D,F=[1]*N,[0]*N,[0]*N
t=1
for i in R:
 if C[i]:d(i)
for i in R:print(i+1,D[i],F[i])

Python: n=int(input())
G=[]
for i in range(n):
    u,k,*l=map(int,input().split())
    G.append(l)
#print(G)
log_finish=[0]*n
log_start=[0]*n

from collections import deque
def dfs(G):
    q=deque()
    for i in range(n,0,-1):
        q.append((i,-1,0))
    log_finish[0]=1
    log_start[0]=1
    cnt=0
    while q:
        #print(q,cnt)
        V,P,S=q.pop()
        if log_finish[V-1]==0 or log_finish[V-1]==log_start[V-1]:
            cnt+=1
            if not log_finish[V-1]:log_start[V-1]=cnt
            log_finish[V-1]=cnt
        #print(V,P,S,cnt)


        if S==0:
            #下に遷移していくときの処理
            q.append((V,P,1))
            l=[]
            if not G[V-1]:continue
            for new_v in G[V-1]:
                if log_start[new_v-1]!=0:continue
                l.append((new_v,V,0))
            q+=l[::-1]

dfs(G)
for i in range(n):
    print(i+1,log_start[i],log_finish[i])

Python: def curserch(N,k,t,P,n):
    g = 0
    t = t+1
    P[k]["d"] = t
    for i in range(1,n+1):
        if N[k][i]==1 and P[i]["d"]==0:
            P[i]["f"] = g = curserch(N,i,t,P,n)
    if g !=0:
        return g+1
    else:
        return t+1

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