Go: package main

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

/***************************************************************
stackによる深さ優先探索を実装する。
***************************************************************/

const (
	N     = 100
	WHITE = 0
	GRAY  = 1
	BLACK = 2
)

var (
	n            int
	Adj          [N][N]int
	statusColor  [N]int
	discoverTime [N]int
	finishTime   [N]int
	clock        int
	nt           [N]int
)

/***************************************************************
Stackの定義:
- field
	container: ノードの格納されたスライス
	sp: スタックポインタ
- method
	size(): スタックに積まれているノードの個数を返す
	top(): スタックの一番上に積まれているノードを返す
	isEmpty(): スタックが空かどうかを返す
	pop(): スタックの要素をポップし削除する
	push(): スタックに要素を積む
***************************************************************/

type Stack struct {
	container []int
	sp        int
}

func (s *Stack) size() int {
	return len(s.container)
}

func (s *Stack) top() int {
	return s.container[s.sp]
}

func (s *Stack) isEmpty() bool {
	return s.sp == 0
}

func (s *Stack) pop() int {
	_pop := func() {
		s.container = s.container[:len(s.container)-1]
	}
	defer _pop()
	if s.isEmpty() {
		panic("There is no elements in stack!")
	}
	s.sp--
	return s.container[s.sp]
}

func (s *Stack) push(n int) {
	s.sp++
	s.container[s.sp] = n
}

func next(u int) int {
	for v := nt[u]; v < n; v++ {
		nt[u] = v + 1
		if Adj[u][v] == 1 {
			return v
		}
	}
	return -1
}

func _DFS(target int) {
	for i := 0; i < n; i++ {
		nt[i] = 0
	}
	stack := new(Stack)
	stack.container = make([]int, N+1)
	stack.push(target)
	statusColor[target] = GRAY
	clock++
	discoverTime[target] = clock
	for !stack.isEmpty() {
		u := stack.top()
		v := next(u)
		if v != -1 {
			if statusColor[v] == WHITE {
				statusColor[v] = GRAY
				clock++
				discoverTime[v] = clock
				stack.push(v)
			}
		} else {
			stack.pop()
			statusColor[u] = BLACK
			clock++
			finishTime[u] = clock
		}
	}
}

func DFS() {
	for i := 0; i < n; i++ {
		statusColor[i] = WHITE
		nt[i] = 0
	}
	clock = 0
	for i := 0; i < n; i++ {
		if statusColor[i] == WHITE {
			_DFS(i)
		}
	}
	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", i+1, discoverTime[i], finishTime[i])
	}
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	scanner.Scan()
	n, _ = strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			Adj[i][j] = 0
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		u, _ := strconv.Atoi(scanner.Text())
		scanner.Scan()
		k, _ := strconv.Atoi(scanner.Text())
		u--
		for j := 0; j < k; j++ {
			scanner.Scan()
			v, _ := strconv.Atoi(scanner.Text())
			v--
			Adj[u][v] = 1
		}
	}

	DFS()
}

Python: class Node():
    def __init__(self, v):
        self.d = 0
        self.f = 0
        self.v = v

    def __repr__(self):
        return "Node({},{},{})".format(
            self.d, self.f, self.v)


def read_node():
    n = int(input())
    adj_list = [[] for _ in range(n + 1)]

    for _ in range(n):
        id, _, *v = [int(x) for x in input().split()]
        adj_list[id] = Node(v)

    return adj_list


def depth_first_search(adj_list):
    def dfs(id):
        nonlocal adj_list, timestamp

        adj_list[id].d = timestamp
        for adj_id in adj_list[id].v:
            if adj_list[adj_id].d == 0:
                timestamp += 1
                dfs(adj_id)
        timestamp += 1
        adj_list[id].f = timestamp

    timestamp = 1
    for id in range(1, len(adj_list)):
        if adj_list[id].d == 0:
            dfs(id)
            timestamp += 1


def print_result(adj_list):
    for id in range(1, len(adj_list)):
        print(id, adj_list[id].d, adj_list[id].f)


def main():
    adj_list = read_node()
    depth_first_search(adj_list)
    print_result(adj_list)


if __name__ == '__main__':
    main()

Python: n = int(input())
adjacency_list = []
for i in range(n):
    input_list = list(map(int, input().split()))
    adjacency_list.append(input_list[2:])
checked_set = set()
dfs_stack = []
v =[0 for i in range(n)]
f =[0 for i in range(n)]
time = 1
for i in range(n):
    if i not in checked_set:
        dfs_stack = []
        dfs_stack.append(i)
        while dfs_stack:
            current = dfs_stack.pop()
            if current not in checked_set:
                checked_set.add(current)
                v[current] = time
                dfs_stack.append(current)
                for ad in reversed(adjacency_list[current]):
                    if ad-1 not in checked_set:
                        dfs_stack.append(ad-1)
                time +=1
            elif f[current] == 0:
                f[current] = time
                time +=1
for i in range(n):
    print(f'{i+1} {v[i]} {f[i]}')

Python: 
WHITE = 0
GRAY = 1
BLACK = 2

NIL = -1


def dfs(u):
    global time
    color[i] = GRAY
    time += 1
    d[u] = time
    for v in range(n):
        if m[u][v] and (color[v] == WHITE):
            dfs(v)
        color[u] = BLACK
    time += 1
    f[u] = time


def next(u):
    for v in range(nt[u], n + 1):
        nt[u] = v + 1
        if m[u][v]:
            return v
    return NIL
            


n = int(input())

m = [[0 for i in range(n + 1)] for j in range(n + 1)]
vid = [0] * n
d = [0] * n
f = [0] * n
S = []
color = [WHITE] * n
time = 0
nt = [0] * n

tmp = []
for i in range(n):
    nums=list(map(int,input().split()))
    tmp.append(nums)
    vid[i] = nums[0]

for i in range(n):
    for j in range(tmp[i][1]):
        m[i][vid.index(tmp[i][j + 2])] = 1

for i in range(n):
    if color[i] == WHITE:
        dfs(i)

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

Python: # input
n = int(input())
A = [[0 for i in range(n)] for j in range(n)]

for i in range(n):
    u, k, *v_list = list(map(int, input().split()))
    for v in v_list:
        A[u-1][v-1] = 1

# init
d = [0] * n
f = [0] * n
t = 0

# recursive
def dfs(u):
    global t
    t += 1
    d[u] = t
    for v in range(n):
        if A[u][v] == 1 and d[v] == 0:
            dfs(v)
    t += 1
    f[u] = t

# dfs
for i in range(n):
    if d[i] == 0:
        dfs(i)

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

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(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)

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