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: 
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])