Go: #include <bits/stdc++.h>
using namespace std;
static const int WHITE = 0;
static const int GRAY  = 1;
static const int BLACK = 2;
static const int N     = 100;

int n, tt;
vector<vector<int>> M(N, vector<int>(N));
vector<int> color(N), d(N), f(N);

void dfs_visit(int u) {
  color[u] = GRAY;
  d[u]     = ++tt;
  for (int v = 0; v < n; v++) {
    if (M[u][v] == 0) continue;
    if (color[v] == WHITE) { dfs_visit(v); }
  }
  color[u] = BLACK;
  f[u]     = ++tt;
}

void dfs() {
  tt = 0;

  for (int u = 0; u < n; u++) {
    if (color[u] == WHITE) dfs_visit(u);
  }
  for (int u = 0; u < n; u++) {
    printf("%d %d %d\n", u + 1, d[u], f[u]);
  }
}

int main() {
  int u, v, k;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
    u--;
    for (int j = 0; j < k; j++) {
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  dfs();
}

Python: n = int(input())
mat = [[0] * n for _ in range(n)]
d, f = [0] * n, [0] * n
for _ in range(n):
    adj = list(map(int, input().split()))
    i = adj[0]
    v = adj[2:]
    for j in v:
        mat[i - 1][j - 1] = 1

time, current = 1, 0
stack = []
d[current] = time
while 0 in f:
    if not stack:
        stack.append(0)
    time += 1
    current = stack[-1]
    for i in range(len(mat[current])):
        if mat[current][i] and not d[i]:
            current = i
            d[i] = time
            stack.append(i)
            break
    else:
        f[current] = time
        current = stack.pop()

for l in zip(range(1, n + 1), d, f):
    print(*l)

Python: from collections import deque

#スタックを使った深さ優先探索の実装
l = int(input())
rlist = []
for i in range(l):
    li = list(map(int, input().split()))
    rlist.append(deque([ll-1 for ll in li[2:]]))


color = ['white'] * l
find_time = [0] * l
stop_time = [0] * l
stack = []
time = 0

def dfs(u):
    global time

    stack.append(u)
    color[u] = 'gray'
    time += 1
    find_time[u] = time

    while len(stack) > 0:
        #print(stack)
        #print(color)
        #print(rlist)

        u = stack[-1]
        #頂点uにまだ訪問すべき頂点が残っているなら
        if len(rlist[u]) > 0:
            if color[rlist[u][0]] == 'white':
                time += 1
                find_time[rlist[u][0]] = time
                color[rlist[u][0]] = 'gray'
                stack.append(rlist[u][0])
            rlist[u].popleft()
        #頂点uにもう訪問すべき頂点が残っていないなら
        else:
            time += 1
            stop_time[u] = time
            color[u] = 'black'
            stack.pop()

for i in range(l):
    if color[i] == 'white':
        dfs(i)
for i in range(len(find_time)):
    print(str(i+1) + ' ' + str(find_time[i]) + ' ' + str(stop_time[i]))

Python: def depth_search(u, t):
    t += 1
    s.append(u)
    d[u] = t
    for v in range(N):
        if adjacency_list[u][v] == 0:
            continue 
        if d[v] == 0 and v not in s:
            t = depth_search(v, t)
    t += 1
    s.pop()
    f[u] = t
    return t

N = int(input())
adjacency_list = [[0 for j in range(N)] for i in range(N)]
for _ in range(N):
    u, k, *v = input().split()
    for i in v:
        adjacency_list[int(u)-1][int(i)-1] = 1

s = []
d = [0 for _ in range(N)]
f = [0 for _ in range(N)]

t = 0
for u in range(N):
    if d[u] == 0:
        t = depth_search(u, t)

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

Python: def visit(u):
    global visit_color, d, f, t
    color[u] = GRAY
    d[u] += t
    t += 1
    for v in range(n):
        if (M[u][v] == 0):
            continue
        else:
            if (color[v] == WHITE):
                visit(v)
    color[u] = BLACK
    f[u] = t
    t += 1

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

for u in range(n):
    if (color[u] == WHITE):
        visit(u)
for u in range(n):
    print(str(u+1), str(d[u]), str(f[u]), sep = " ")

Python: from sys import stdin
n = int(stdin.readline())
M = [list(map(int, stdin.readline().split()[2:])) for i in range(n)]
sndf = [[False, i] for i in range(1, n + 1)]
tt = 0
def dfs(u):
    global tt
    sndf[u][0] = True
    tt += 1
    sndf[u].append(tt)
    for v in M[u]:
        v -= 1
        if not sndf[v][0]:
            dfs(v)
    tt += 1
    sndf[u].append(tt)
for i in range(0, n):
    if not sndf[i][0]:
        dfs(i)
    print(*sndf[i][1:])

Python:    #depth first
N=int(input())
V=[]
a=[0]
for i in range(N):
    V.append([int(i) for i in input().split()])
    w=V[i][2:]
    w.sort()
    V[i]=V[i][:2]+w
    a.append(0)
V=sorted(V,key=lambda x:x[0])
c=1
t=1
i=0
r=[1]
a[1]=1
p=[[1,t]]
q=[]
while t<N*2:
    j=2
    while t<N*2 and j-2<V[i][1] and V[i][1]>0 and a[V[i][j]]==1:
        j+=1
    t+=1
    if j-2<V[i][1]:
        a[V[i][j]]=1
        c+=1
        r.append(V[i][j])
        p.append([V[i][j],t])
        i=V[i][j]-1
    else:
        q.append(p[-1]+[t])
        r.pop(-1)
        p.pop(-1)
        if len(r)>0:
            i=r[-1]-1
        else:
            j=1
            while j<N and a[j]==1:
                j+=1
            if j<N:
                t+=1
                i=j-1
                r.append(j)
                p.append([j,t])
q=sorted(q,key=lambda x:x[0])
for i in range(N):
    for j in range(3):
        q[i][j]=str(q[i][j])
    print(" ".join(q[i]))

Python: def DFS(num):
    global time
    time +=1
    color[num]="gray"
    D[num][0]=time
    for i in M[num]:
        if color[i]=="white":
            DFS(i)
    color[num]="black"
    time +=1
    D[num][1]=time


n=int(input())
M=[[] for _ in range(n+1)]
for i in range(n):
    for j in list(map(int,input().split()))[2:]:
        M[i+1].append(j)
color=["white" for _ in range(n+1)]
D=[[0,0] for _ in range(n+1)]
time=0
for i in range(n):
    if color[i+1]=="white":
        DFS(i+1)

for i in range(n):
    print(i+1,*D[i+1])

Python: n=int(input())

next=[[] for i in range(n)]
for i in range(n):
	l=list(map(int,input().split()))
	u=l[0]
	k=l[1]
	for j in range(2,k+2):
		next[u-1].append(l[j]-1)

stk=[]
stk.append(0)
time=1
d=[0 for i in range(n)]
f=[0 for i in range(n)]
know=[0 for i in range(n)]

def dfs(x):
	global time
	know[x]=1
	d[x]=time
	time+=1
	for n in next[x]:
		if know[n]==0:
			dfs(n)
	f[x]=time
	time+=1
	
for i in range(n):
	if know[i]==0:
		dfs(i)

for i in range(n):
	out=[]
	out.append(i+1)
	out.append(d[i])
	out.append(f[i])
	print(*out)

Python: # -*- coding: utf-8 -*-

import sys
sys.setrecursionlimit(10 ** 9)
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
INF=float('inf')

N=INT()
nodes=[[] for i in range(N)]
for i in range(N):
    l=LIST()
    u=l[0]
    l=l[2:]
    for v in l:
        nodes[u-1].append(v-1)
    nodes[u-1].sort()

ans=[[0]*2 for i in range(N)]
visited=[False]*N
time=0
def rec(u):
    if visited[u]:
        return
    visited[u]=True
    global time
    time+=1
    ans[u][0]=time
    for v in nodes[u]:
        rec(v)
    time+=1
    ans[u][1]=time

for i in range(N):
    rec(i)
for i in range(N):
    d,f=ans[i]
    print(i+1, d, f)