Go: package main

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

type TimeRecord struct {
	discoverTime int
	finishTime   int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	timeRecordMap := make([]TimeRecord, n)
	childrenMap := make([][]int, n)
	for i := 1; i <= n; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		timeRecordMap[node-1] = TimeRecord{-1, -1}

		childNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		childrenMap[node-1] = make([]int, childNum)
		for j := 0; j < childNum; j++ {
			child, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			childrenMap[node-1][j] = child
		}
	}

	timer := 1
	startNode := 1
	for {
		visit(startNode, &timer, childrenMap, timeRecordMap)
		startNode = findStartNode(childrenMap, timeRecordMap)
		if startNode < 0 {
			break
		}
	}
	for k, v := range timeRecordMap {
		fmt.Printf("%d %d %d\n", k+1, v.discoverTime, v.finishTime)
	}
}

func findStartNode(childrenMap [][]int, timeRecordMap []TimeRecord) int {
	x := -1
	for node, timeRecord := range timeRecordMap {
		if timeRecord.discoverTime < 0 {
			x = node + 1
			break
		}
	}
	return x
}

func visit(currentNode int, timer *int, childrenMap [][]int, timeRecordMap []TimeRecord) {
	if timeRecordMap[currentNode-1].discoverTime > 0 {
		return
	}
	children := childrenMap[currentNode-1]
	timeRecordMap[currentNode-1] = TimeRecord{*timer, timeRecordMap[currentNode-1].finishTime}
	(*timer)++
	for i := 0; i < len(children); i++ {
		visit(children[i], timer, childrenMap, timeRecordMap)
	}
	timeRecordMap[currentNode-1] = TimeRecord{timeRecordMap[currentNode-1].discoverTime, *timer}
	(*timer)++
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

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

Python: def h(G,G1,d,f,c,tmp,tmp1,n):
    if c[0]==2:
        f[0]=f[tmp]+1
        return 0
    cnt=0
    for i in range(n):
        if G1[tmp1][i]==1:
            if c[i]==0:
                d[i]=d[tmp1]+1
                c[i]+=1
                tmp=tmp1
                tmp1=i
                G1[tmp][i]=0
                h(G,G1,d,f,c,tmp,tmp1,n)

        else:
            cnt+=1
            if cnt==n:
                if c[tmp1]==1:
                    d[tmp1]=d[tmp]+1
                    c[tmp1]+=1
                    f[tmp1]=d[tmp1]+1
                    tmp=tmp1
                    for j in range(n):
                        if G[j][tmp]==1:
                            tmp1=j
                    G1[j][tmp1]=0
                    c[tmp1]+=1
                    h(G,G1,d,f,c,tmp,tmp1,n)
                elif c[tmp1]==2:
                    f[tmp1]=f[tmp]+1
                    tmp=tmp1
                    for j in range(n):
                        if G[j][tmp]==1:
                           tmp1=j
                           G1[j][tmp]=0
                    c[tmp1]+=1
                    h(G,G1,d,f,c,tmp,tmp1,n)
n=int(input())
d=[1 for i in range(n)]
f=[0 for i in range(n)]
c=[0 for i in range(n)]
G=[[0 for i in range(n)]for j in range(n)]
G1=[[0 for i in range(n)]for j in range(n)]
u=[0 for i in range(n)]
for i in range(n):
    A=input().split()
    u[i]=int(A[0])
    k=int(A[1])
    for j in range(k):
        x=int(A[j+2])-1
        G[i][x]=1
        G1[i][x]=1

d[0]=1
c[0]+=1
for i in range(n):
    if G[0][i]==1:
        d[i]=d[0]+1
        c[i]+=1
        tmp=0
        tmp1=i
        G1[0][i]=0
        break
h(G,G1,d,f,c,tmp,tmp1,n)
for i in range(n):
    print(i+1,d[i],f[i])