Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const N = 100

const (
	WHITE = iota
	GRAY
	BLACK
)

type Graph struct {
	M               [N][N]int
	color, d, f, nt [N]int
	tt              int
}

func (g *Graph) next(u, n int) int {
	for v := g.nt[u]; v < n; v++ {
		g.nt[u] = v + 1
		if g.M[u][v] != 0 {
			return v
		}
	}
	return -1
}

func (g *Graph) dfsVisit(r, n int) {
	var S []int
	S = append([]int{r}, S...)
	g.color[r] = GRAY
	g.tt++
	g.d[r] = g.tt

	for len(S) != 0 {
		u := S[0]
		v := g.next(u, n)
		if v == -1 {
			S = S[1:]
			g.color[u] = BLACK
			g.tt++
			g.f[u] = g.tt
			continue
		}

		if g.color[v] != WHITE {
			continue
		}

		g.color[v] = GRAY
		g.tt++
		g.d[v] = g.tt
		S = append([]int{v}, S...)
	}
}

func (g *Graph) dfs(n int) string {
	for i := 0; i < n; i++ {
		g.color[i] = WHITE
	}
	g.tt = 0

	for u := 0; u < n; u++ {
		if g.color[u] == WHITE {
			g.dfsVisit(u, n)
		}
	}

	var out bytes.Buffer
	for i := 0; i < n; i++ {
		out.WriteString(fmt.Sprintf("%d %d %d\n", i+1, g.d[i], g.f[i]))
	}

	return strings.TrimRight(out.String(), "\n")
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	var g Graph
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		u--
		for j := 0; j < k; j++ {
			sc.Scan()
			v, _ := strconv.Atoi(sc.Text())
			v--
			g.M[u][v] = 1
		}
	}

	return g.dfs(n)
}

func main() {
	fmt.Println(answer(os.Stdin))
}

Python: import sys


def input():
    return sys.stdin.readline().rstrip()


def dfs(c, n, G, ans):
    count = c
    for i, flag in enumerate(G[n]):
        if flag == 1 and ans[i][0] == 0:
            count += 1
            ans[i][0] = i + 1
            ans[i][1] = count
            ans[i][2] = dfs(count, i, G, ans)
            count = ans[i][2]
    else:
        return count + 1


def main():
    n = int(input())
    G = [[0] * n for _ in range(n)]
    ans = [[0] * 3 for _ in range(n)]
    for i in range(n):
        u, k, *v = map(int, input().split())
        for j in range(k):
            G[u-1][v[j]-1] = 1

    count = 1
    for i in range(n):
        if ans[i][0] == 0:
            ans[i][0] = i + 1
            ans[i][1] = count
            ans[i][2] = dfs(count, i, G, ans)
            count = ans[i][2] + 1

    for i in range(n):
        print(*ans[i])


if __name__ == '__main__':
    main()

Python: from collections import deque

n = int(input())

g = [deque([]) *n for _ in range(n)]

for i in range(n):
    u, k, *V = list(map(int, input().split()))
    V.sort()
    for v in V:
        g[u-1].append(v-1)
        # g[v-1].append(u-1)

time = 0
arrive_time = [-1] * n
finish_time = [-1] * n
def dfs(v):
    global time
    time += 1
    stack = [v]
    arrive_time[v] = time
    while stack:
        v = stack[-1]
        if g[v]:
            w = g[v].popleft()
            if arrive_time[w] < 0:
                time += 1
                arrive_time[w] = time
                stack.append(w)
        else:
            time += 1
            finish_time[v] = time
            stack.pop()

    return [arrive_time, finish_time]

for i in range(n):
    if arrive_time[i] < 0:
        ans = dfs(i)

for j in range(n):
    temp = [j+1, ans[0][j], ans[1][j]]
    print(*temp)

Python: N = int(input())
adj_list = []
for _ in range(N):
    line = list(input().split(" "))
    adj_list.append([int(k) - 1 for k in line[2:]])

d = [-1 for _ in range(N)]
f = [-1 for _ in range(N)]
time = 1

visited = set()

def dfs(p):
    global time
    if p in visited:
        return

    d[p] = time
    time += 1
    visited.add(p)
    for ad in adj_list[p]:
        if ad not in visited:
            dfs(ad)
    f[p] = time
    time += 1

for i in range(N):
    dfs(i)

for i in range(N):
    print(f"{i + 1} {d[i]} {f[i]}")

Python: # coding: utf-8
# Your code here!

n = int(input())
M = []
for i in range(n):
    adj = list(map(int,input().split()))
    if adj[1] == 0:
        M += [[]]
    else:
        M += [adj[2:]]
time = 1
ans = [[j+1,0,0] for j in range(n)] # id d f

while True:
    for i in range(n):
        if ans[i][1] == 0:
            stack = [i]
            ans[i][1] = time
            time += 1
            break
        elif i == n-1:
            for k in range(n):
                print(*ans[k])
            exit()
    while stack != []:
        u = stack[-1]
        if M[u] != []:
            for i in range(len(M[u])):
                v = M[u][0]
                M[u].remove(v)
                if ans[v-1][1] == 0:
                    ans[v-1][1] = time
                    stack.append(v-1)
                    time += 1
                    break
        else:
            stack.pop()
            ans[u][2] = time
            time += 1

Python: n=int(input())
G=[]
for i in range(n):
    L=list(map(int,input().split()))
    G.append(L[2:])
    for j in range(len(G[-1])):
        G[-1][j]-=1

Forder=[-1]*n
Lorder=[-1]*n
ptr=1
def dfs(v):
    #print(v)
    #print(G[v])
    #print()
    global ptr

    Forder[v]=ptr
    ptr+=1

    for next in G[v]:
        if Forder[next]!=-1:
            continue
        dfs(next)
    
    Lorder[v]=ptr
    ptr+=1

#while True:
#    #print(Forder,Lorder)
#    for i in range(n):
#        if Forder[i]!=-1 and Lorder[i]!=-1:
#            pass
#        else:
#            dfs(i)
#            continue
#
#        if i==n-1:
#            break
#    else:
#        continue
#    break
#
#for i in range(n):
#    print(i+1,Forder[i],Lorder[i])

##########
for i in range(n):
    if Forder[i]==-1 or Lorder[i]==-1:
        dfs(i)

for i in range(n):
    print(i+1,Forder[i],Lorder[i])

Python: n = int(input())
Adj = [[0 for i in range(n)] for i in range(n)]
 
for i in range(n):
    u = list(map(int, input().split()))
    if u[1] > 0:
        for i in u[2: 2 + u[1]]:
            Adj[u[0] - 1][i - 1] = 1
 
color = [0] * n
d = [0] * n
f = [0] * n
time = 0
def dfs(u):
    global time
    color[u - 1] = 1
    time += 1
    d[u - 1] = time
    for i in range(1, n+1):
        if Adj[u - 1][i - 1] == 1 and color[i - 1] == 0:
            dfs(i)
    color[u - 1] = 2
    time += 1
    f[u - 1] = time

for i in range(1, n+1):
    if color[i-1] == 0:
        dfs(i)
for i in range(n):
    print("{} {} {}".format(i+1,d[i],f[i]))

Python: def dfs(u, colors, matrix, time, detect_time, finished_time):
    # ????????????????????¨??????????????????
    colors = colors
    detect_time = detect_time
    finished_time = finished_time
    time = time + 1
    stack = list()
    stack.append(u)
    colors[u] = 1
    detect_time[u] = time
    while len(stack):
        for i, val in enumerate(matrix[u]):
            if i == 2 and val == 1:
                print('tanaka')
            if val == 1 and colors[i] == 0:
                time += 1
                stack.append(i)
                colors[i] = 1
                detect_time[i] = time
                u = i
                break
        else:
            time += 1
            e = stack.pop()
            colors[e] = 2
            finished_time[e] = time
            if len(stack):
                u = stack[-1]
    return time


if __name__ == '__main__':
    N = int(input())
    matrix = [[0] * N for _ in range(N)]
    color = [0] * N
    for i in matrix:
        node_info = [int(i) for i in input().split()]
        node_i = node_info[0] - 1
        if not node_info[1] == 0:
            for i in node_info[2:]:
                matrix[node_i][i - 1] = 1
    colors = [0] * len(matrix)
    detect_time = [0] * len(matrix)
    finished_time = [0] * len(matrix)
    time = 0
    for i, val in enumerate(colors):
        if val == 0:
            time = dfs(i, colors, matrix, time, detect_time, finished_time)

    for i in range(len(matrix)):
        print('{} {} {}'.format(i + 1, detect_time[i], finished_time[i]))