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: from collections import deque
n = int(input())
v = {i:[] for i in range(n)}
for i in range(n):
    u = list(map(int, input().split()))
    for j in range(2, 2+u[1]):
        v[u[0]-1].append(u[j]-1)

global cnt1 
cnt1 = 0
visited = [False for _ in range(n)]
f = [0 for _ in range(n)]
l = [0 for _ in range(n)]
def DFS(now, visited):
    global cnt1
    cnt1 += 1
    f[now] = cnt1
    visited[now] = True
    for nv in v[now]:
        if visited[nv]:
            continue
        DFS(nv, visited)
    cnt1 += 1
    l[now] = cnt1

for value in range(n):
    if not visited[value]:
        DFS(value, visited)
    
for i in range(n):
    print(i+1, f[i], l[i])

Python: 
n=int(input())

l=[[0 for i in range(n)] for j in range(n)]##静的確保 隣接行列
d=[0 for i in range(n)]##発見
f=[0 for i in range(n)]##完了
stack=[]##スタック
check=[]

for i in range(n):
    p=[int(x) for x in input().split()]
    
    for j in range(n):
        if j+1 in p[2:]:
            l[i][j]=1
##print("---隣接行列---")
##print(l)

time=1


while len(check)<n:
    for i in range(n):
        if i+1 not in check:
            stack+=[i+1]
            d[i]=time
            break
        else: pass

    while len(stack)!=0:
        ##print("----------while---------")
        for i in range(n):
            if l[stack[-1]-1][i]==1 and not i+1 in check and stack[-1]-1!=i:
                time+=1
                d[i]=time
                stack+=[i+1]

               ## print("stack:",stack)
               ## print("check:",check)
               ## print("d[",i,"]:",d[i])
                break
            elif i==n-1:
##最深    
                check+=[stack[-1]]
                time+=1
                f[stack.pop()-1]=time

               ## print("f[",i,"]:",f[i])
               ## print("check:",check)
    time+=1


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

Python: n = int(input())
B = [[0 for i in range(n)] for j in range(n)]
chk = [0 for i in range(n)]
s = []
i_array = [0 for i in range(n)]
time = 1
node_start_time = [0 for i in range(n)]
node_finish_time = [0 for i in range(n)]

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

for i in range(n):
    if(chk[i] == 1):
        continue
    chk[i] = 1
    node_start_time[i] = time
    time += 1
    s.append(i)
    while(len(s) != 0):
        flag = 0
        v = s[len(s)-1]
        for j in range(i_array[v],n):
            if(B[v][j] == 1 and chk[j] == 0):
                chk[j] = 1
                s.append(j)
                node_start_time[j] = time
                time += 1
                i_array[v] = j+1
                flag = 1
                break
        if(flag == 0):
            s.pop()
            node_finish_time[v] = time
            time += 1

for i in range(n):
    print(i+1,node_start_time[i],node_finish_time[i])

Python: def main():
    n = int(input())
    _next, state, d, f = [], [False] * n, [0] * n, [0] * n
    for _ in range(n):
        u, k, *v = map(lambda s: int(s) - 1, input().split())
        _next.append(sorted(v, reverse=True))
    stack = []
    time = 0

    while True:
        for i in range(n):
            if not state[i]:
                stack.append(i)
                state[i] = True
                time += 1
                d[i] = time
                break
        if not stack:
            break
        while stack:
            u = stack[-1]
            if _next[u]:
                v = _next[u].pop()
                if not state[v]:
                    state[v] = True
                    time += 1
                    d[v] = time
                    stack.append(v)
            else:
                time += 1
                f[u] = time
                stack.pop()

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


if __name__ == '__main__':
    main()

Python: def dfs(v, cnt):
  D[v] = cnt
  cnt += 1
  for c in edge[v]:
    if D[c] == -1:
      cnt = dfs(c, cnt)
  F[v] = cnt
  cnt += 1
  return cnt

N = int(input())
edge = [[] for _ in range(N)]
for _ in range(N):
  u, _, *v = map(lambda x:int(x)-1, input().split())
  edge[u] = sorted(v)
D, F = [-1] * N, [-1] * N
c = 1
for i in range(N):
  if D[i] == -1:
    c = dfs(i, c)
for i, (d, f) in enumerate(zip(D, F)):
  print(i + 1, d, f)

Python: # =============================================================================
#　Depth First Search
# =============================================================================
import sys
sys.setrecursionlimit(10**8)

N=int(input())
Graph=[list(map(int,input().split()))[2:] for _ in range(N)]
Graph.insert(0,[])
seen=[False for _ in range(N+1)]
first_order=[0]*(N+1)
last_order=[0]*(N+1)
time=1

def dfs(Graph,v):
    global seen
    global time
    seen[v]=True
    first_order[v]=time
    time+=1
    for nv in Graph[v]:
        if seen[nv]:
            continue
        dfs(Graph,nv)

    last_order[v]=time
    time+=1

for v in range(1,N+1):
    if not seen[v]:
        dfs(Graph,v)
for i in range(1,N+1):
    print(i,first_order[i],last_order[i])

Python: def dfs(n):
    global t
    S[n] = t
    DP[n]=1
    for i in A[n][2:]:
        if not DP[i]:
            t += 1
            dfs(i)
    t += 1
    F[n] = t
n = int(input())
A = [0]*(n+1)
S = [0]*(n+1)
F = [0]*(n+1)
DP = [0]*(n+1)
for i in range(n):
    A[i+1] = [int(i) for i in input().split()]
t = 0
for i in range(1,n+1):
    if not DP[i]:
        t+=1
        dfs(i)
for i in range(1,n+1):
    tmp = "{} {} {}".format(i,S[i],F[i])
    print(tmp)

Python: import sys
sys.setrecursionlimit(10**7)
time = 0
def input():
    return sys.stdin.readline()
n = int(input())
G = [[]]
d = [0]*(n+1)
f = [0]*(n+1)
for _ in range(n):
    G.append(list(map(int,input().split()))[2:])
def dfs(e):
    global time
    d[e] = time
    for nexte in G[e]:
        if d[nexte] == 0:
            time += 1
            dfs(nexte)
    time += 1
    f[e] = time

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