Go: package main

import "fmt"

type node struct {
	id, d, v int
	adj      []node
}

var n int
var seen []bool
var graph []node

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func dfs(v, t int) int {
	// fmt.Printf("dfs(v %d, t %d) en:\n", v, t)
	seen[v] = true
	graph[v].v = t
	tt := t
	for _, vv := range graph[v].adj {
		if !seen[vv.id] {
			tt = max(tt, dfs(vv.id, tt+1))
		}
	}
	graph[v].d = tt + 1
	// fmt.Printf("dfs(v %d, t %d) ex: d %d\n", v, t, graph[v].d)
	return graph[v].d
}

func main() {
	fmt.Scan(&n)
	graph = make([]node, n+1)
	for i := 1; i <= n; i++ {
		var u, k, v int
		fmt.Scan(&u, &k)
		graph[u].id = u
		// 頂点uはk個の隣接頂点を持っている
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			var t node
			t.id = v
			graph[u].adj = append(graph[u].adj, t)
		}
	}
	// fmt.Println("n", n, "graph", graph)
	seen = make([]bool, n+1)
	// t := dfs(1, 1)
	v, t := 1, 1
	done := false
	for !done {
		tt := dfs(v, t)
		done = true
		for i := range seen {
			if !seen[i] {
				done = false
				v = graph[i].id
				t = tt
				break
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, graph[i].v, graph[i].d)
	}
}

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

edge=[[0 for i2 in range(n)]for i1 in range(n)]

#??£??\???????????????

for i in range(n):
    for j in range(adj[i][1]):
        edge[i][adj[i][j+2]-1]=1

#print(edge)

discover=[0 for i in range(n)]
final=[0 for i in range(n)]
stack=[0]

def dfs(id,time):
    for i in range(n):
        c=0
        if edge[id][i]==1 and discover[i]==0:
            stack.append(id)
            discover[i]=time
            c+=1
            #print(discover,final,i,stack)
            dfs(i,time+1)
        else:
            pass
    if c==0:
        if len(stack)>0:
            if final[id]==0:
                final[id] = time
                #print("back",discover,final,id,stack)
                dfs(stack.pop(), time + 1)
            else:
                #print("back", discover, final, id, stack)
                dfs(stack.pop(),time)

discover[0]=1
dfs(0,2)

for i in range(n):
    print(i+1,discover[i],final[i])

Python: import sys
import itertools
sys.setrecursionlimit(1000000000)
from heapq import heapify,heappop,heappush,heappushpop
import math
import collections
import copy
time = 1
def dfs(node):
    global time
    if visited[node] != -1:
        return
    visited[node] = 0
    d[node] = time
    time += 1
    for v in edge[node]:
        dfs(v)
    f[node] = time
    time += 1

if __name__ == "__main__":
    n = int(input())
    edge = []
    for i in range(n):
        u,k,*v_li = map(int,input().split())
        for j in range(len(v_li)):
            v_li[j] -= 1
        u-=1
        edge.append(v_li)
    d = {}
    f = {}
    visited = [-1]*n
    
    for i in range(n):
        dfs(i)
    for i in range(n):
        print(i+1,d[i],f[i])

Python: # -*- coding: utf-8 -*-
"""
Created on Sun Jul  8 10:56:33 2018

@author: maezawa
"""
n = int(input())
adj = [[] for _ in range(n)]
d = [0 for _ in range(n)]
f = [0 for _ in range(n)]

for j in range(n):
    ain = list(map(int, input().split()))
    u = ain[0]
    k = ain[1]
    for i in range(k):
        adj[u-1].append(ain[i+2]-1)
    adj[u-1].sort()
    #print(*adj[u-1])

t = 1
stack = [0]

while stack:
    print(stack)
    current = stack[-1]
    if d[current] == 0:
        d[current] = t
        t += 1
    flag = 0
    for k in adj[current]:
        if d[k] == 0:
            stack.append(k)
            flag = 1
            break
    if flag == 0:
        f[current] = t
        t += 1
        stack.pop()

    #print('current = {}, t = {}'.format(current, t))
    #print('stack', *stack)

for i in range(n):
    print('{} {} {}'.format(i+1, d[i], f[i]))

Python: def DFS(adj, start):
    n = len(adj)
    d = [0] * n
    f = [0] * n
    flag = [0] * n
    S = []
    time = 1

    S.append(start)
    flag[start] = 1
    d[start] = time
    time = time + 1
    
    while flag.count(2) != n: # ??¨????????????????????¢?´¢????????????????????§
        if len(S) != 0:
            u = S.pop()
            v = next(adj, u)
            v = [i for i in v if flag[i] == 0] # v <= ??£??\???????????????????????¢?´¢??????????????????
            if len(v) != 0:
                S.append(u)
                S.append(v[0])
                flag[v[0]] = 1
                d[v[0]] = time
                time = time + 1
            else:
            #??£??\??????????????¨????¨??????????
                flag[u] = 2
                f[u] = time
                time = time + 1

        else:
            u = flag.index(0)
            S.append(u)
            flag[u] = 1
            d[u] = time
            time = time + 1            

    return d, f



def next(adj, u):
    """
    u?????£??\??????????????????????????????????????????
    """
    return [i for i, x in enumerate(adj[u]) if x == 1]
    

def main():
    
    n = int(input())
    adj = [[0 for i in range(n)] for j in range(n)]

    for i in range(n):
        tmp = list(map(int, input().split()))
        u = tmp[0]
        u = u -1
        k = tmp[1]
        v = tmp[2:]
        for j in range(k):
            adj[u][v[j]-1] = 1
    
    d, f = DFS(adj, 0)
    for i in range(n):
        print(i+1, d[i], f[i])

if __name__ == "__main__":
    main()

Python: # -*- coding: utf_8 -*-

level = False
def debug(v):
    if level:
        print(v)

n = int(input())
a = [0]

for i in range(n):
    v = input().split()
    v.pop(0)
    v.pop(0)
    a.append([int(x) for x in v])

debug(a)
stack = [1]
results = [[0 for i in range(2)] for j in range(n + 1)]
results[0][0] = 0
time = 0


def depth_first_search(a, stack):
    debug(a)
    debug(results)
    debug(stack)
    global time
    if len(stack) == 0:
        return

    v = stack.pop()
    if results[v][0] == 0:
        time += 1
        results[v][0] = time

    es = a[v]
    if len(es) == 0 and results[v][1] == 0:
        time += 1
        results[v][1] = time

    if len(es) != 0:
        stack.append(v)
        stack.append(es.pop(0))

    depth_first_search(a, stack)

for i in range(n):
    stack = [i + 1]
    depth_first_search(a, stack)

debug(results)

results.pop(0)

i = 1
for row in results:
    print(str(i) + " " + str(row[0]) + " " + str(row[1]))
    i += 1

Python: time=1
num=0
n=int(input())

A=[[] for i in range(n)]
d=[0 for i in range(n)]
f=[0 for i in range(n)]

for i in range(n):
	a=list(map(int,input().split()))
	for j in range(a[1]):
		A[i].append(a[2+j]-1)

def dfs(q,num):
	global d,f,time
	d[num]=time
	for nx in q[num]:
		if d[nx]==0:
			time+=1
			dfs(q,nx)
	time+=1
	f[num]=time
	

dfs(A,num)

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

Python: def visit(u):
    global color, d, f, t
    color[u] = GRAY
    d[u] += t
    t += 1
    for v in range(n):
        if (M[u][v] == 0):
            continue
        else:
            if (color[v] == WHITE):
                visit(v)
    color[u] = BLACK
    f[u] = t
    t += 1

n = int(input())
M = [[0 for i in range(n)] for i in range(n)]
for i in range(n):
    tmp = list(map(int, input().split()))
    for i in range(tmp[1]):
        M[tmp[0]-1][tmp[i+2]-1] = 1

WHITE = 0
GRAY = 1
BLACK = 2
color = [WHITE for i in range(n)]
d, f = [0 for i in range(n)]
t = 1
for u in range(n):
    if (color[u] == WHITE):
        visit(u)
for u in range(n):
    print(str(u+1), str(d[u]), str(f[u]), sep = " ")