Go: package main

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

var N int
var A [][]int
var t int
var color, d, f []int

const (
	WHITE = iota
	GRAY
	BLACK
)

func dfsVisit(u int) {
	color[u] = GRAY
	t ++
	d[u] = t
	for v:=0; v<N; v++ {
		if A[u][v] == 0 {
			continue
		}
		if color[v] == WHITE {
			dfsVisit(v)
		}
	}
	color[u] = BLACK
	t++
	f[u] = t
}

func dfs() {
	for u:=0; u<N; u++ {
		if color[u] == WHITE {
			dfsVisit(u)
		}
	}
	for u:=0; u<N; u++{
		fmt.Printf("%d %d %d\n", u+1, d[u], f[u])
	}
}


func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	N = nextInt(scanner)
	color = make([]int, N)
	d = make([]int, N)
	f = make([]int, N)
	A = make([][]int, N)
	for i:=0; i<N; i++{
		A[i] = make([]int, N)
	}
	for i:=0; i<N; i++{
		index := nextInt(scanner) - 1
		cnt := nextInt(scanner)
		for j:=0; j<cnt; j++ {
			v := nextInt(scanner) - 1
			A[index][v] = 1
		}
	}
	dfs()
}

Python: import sys
from collections import defaultdict


time = 1


def dfs(g, visited, start, ans):
    global time
    visited[start - 1] = True
    ans[start - 1][0] = time
    for e in g[start]:
        if not visited[e - 1]:
            time += 1
            dfs(g, visited, e, ans)
    time += 1
    ans[start - 1][1] = time


def main():
    input = sys.stdin.buffer.readline
    n = int(input())
    g = defaultdict(list)
    for i in range(n):
        line = list(map(int, input().split()))
        if line[1] > 0:
            g[line[0]] = line[2:]
    visited = [False] * n

    ans = [[1, 1] for _ in range(n)]
    global time
    while False in visited:
        start = visited.index(False) + 1
        dfs(g, visited, start, ans)
        time += 1

    for i in range(1, n + 1):
        print(i, *ans[i - 1])


if __name__ == "__main__":
    main()

Python: from sys import stdin
n = int(stdin.readline())
M = [None] + [list(map(int, stdin.readline().split()[2:])) for i in range(n)]
sndf = [None] + [[False, i] for i in range(1, n + 1)]
tt = 0
def dfs(u):
    global tt
    sndf[u][0] = True
    tt += 1
    sndf[u].append(tt)
    for v in M[u]:
        if not sndf[v][0]:
            dfs(v)
    tt += 1
    sndf[u].append(tt)
for i in range(1, n + 1):
    if not sndf[i][0]:
        dfs(i)
for x in sndf[1:]:
    print(*x[1:])

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

Python: import sys

sys.setrecursionlimit(10 ** 7)
input = sys.stdin.readline
f_inf = float('inf')
mod = 10 ** 9 + 7
idx = 1


def resolve():
    def dfs(v):
        global idx
        begin[v] = idx
        idx += 1
        for u in edge[v]:
            if begin[u] != 0:
                continue
            else:
                dfs(u)
        end[v] = idx
        idx += 1

    n = int(input())
    edge = [[] for _ in range(n)]
    for _ in range(n):
        u, k, *V = map(int, input().split())
        for v in V:
            edge[u - 1].append(v - 1)

    begin = [0] * n
    end = [0] * n
    for i in range(n):
        if begin[i] == 0:
            dfs(i)
    for i in range(n):
        print(i + 1, begin[i], end[i])


if __name__ == '__main__':
    resolve()

Python: # Graph I - Depth First Search
def dfs(idx,A):
    global time,d,f
    d[idx] = time
    time += 1
    for i,v in enumerate(A[idx]):
        if v == 1 and d[i] == 0:
            dfs(i,A)
    f[idx] = time
    time += 1

n = int(input())
A = []
for _ in range(n):
    ss = list(map(int, input().split()))
    u = ss[0] - 1
    row = [0 for _ in range(n)]
    for i in range(ss[1]):
        idx = 2 + i
        row[ss[idx]-1] = 1
    A.append(row)

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

for i,t in enumerate(zip(d,f)):
    print(i+1,t[0],t[1])

Python: n = int(input())
graph = [[0 for i in range(n)] for j in range(n)]
d = [0] * n
f = [0] * n
g = [0] * n

time = 0

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

def search(i):
    global time
    time = time + 1
    d[i] = time
    g[i] = 1
    for j in range(i, n):
        if (graph[i][j] == 1) & (g[j] == 0):
            search(j)
    time = time + 1
    f[i] = time if f[i] == 0 else f[i]


search(0)
[print(i+1, d[i], f[i]) for i in range(n)]

Python: INTERVAL = 1
WHITE = 0
GRAY = 1
BLACK = 2


def depth_first_search(u):
    global time

    time += INTERVAL
    d[u] += time
    color[u] = GRAY

    for v in range(n):
        if matrix[u][v] and color[v] == WHITE:
            depth_first_search(v)

    time += INTERVAL
    f[u] += time
    color[u] = BLACK

# INPUT
n = int(input())


time = 0
color = [WHITE] * n
d = [0] * n
f = [0] * n

matrix = [[0] * n for _ in range(n)]

for i in range(n):

    u, k, *V = map(int, input().split())

    for v in V:
        v -= 1
        matrix[i][v] = 1


# PROCESS
u_search = 0
while True:

    depth_first_search(u_search)

    if WHITE not in color:
        break
    else:
        u_search = color.index(WHITE)
        

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

Python: if __name__ == '__main__':
    n = int(input())
    graph = [[0 for i in range(n)] for _ in range(n)]
    frist = [0 for _ in range(n)]
    end = [0 for _ in range(n)]
    visit = [False for _ in range(n)]
    # get the group
    for i in range(n):
        datas = [int(num) for num in input().split(' ')]
        if datas[1] > 0:
            for j in datas[2:]:
                graph[datas[0] - 1][j - 1] = 1

    visit[0] = True
    frist[0] = s = 1
    stack = [0]

    while len(stack) != 0:
        point = stack.pop(-1)
        flag = False
        for i in range(n):
            if graph[point][i] == 1 and visit[i] is False:
                visit[i] = True
                flag = True
                s += 1
                frist[i] = s
                stack.append(point)
                stack.append(i)
                break
        if flag is False:
            s += 1
            end[point] = s
        
        if len(stack) == 0:
            for i in range(n):
                if visit[i] is False:
                    visit[i] = True
                    s += 1
                    frist[i] = s
                    stack.append(i)
                    break
            
    for i in range(n):
        print('%d %d %d' % (i+1, frist[i], end[i]))

Python: #ALDS_11_B - 深さ優先探索
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**9)#再帰回数の上限

def DFS(u, cnt):
    visited.add(u)
    first_contact = cnt
    
    cnt += 1
    for nb in edge[u]:
        if nb not in visited:
            cnt = DFS(nb, cnt)
    
    stamp[u] = first_contact, cnt
    return cnt+1
    

N = int(input())
edge = [[] for i in range(N)]
for _ in range(N):
    tmp = list(map(int,input().split()))
    if tmp[1] != 0:
        edge[tmp[0]-1] = list(map(lambda x: int(x-1),tmp[2:]))

stamp = [None]*N
visited = set()

c = 1
for i in range(N):
    if i not in visited:
        c = DFS(i, c)
        
for i,s in enumerate(stamp):
    print(i+1,*s)