Go: package main

import "fmt"

type node struct {
	id, d, v int
	adj      []node
}

var n int
var seen []bool
var graph []node

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func dfs(v, t int) int {
	// fmt.Printf("dfs(v %d, t %d) en:\n", v, t)
	seen[v] = true
	graph[v].v = t
	tt := t
	for _, vv := range graph[v].adj {
		if !seen[vv.id] {
			tt = max(tt, dfs(vv.id, tt+1))
		}
	}
	graph[v].d = tt + 1
	// fmt.Printf("dfs(v %d, t %d) ex: d %d\n", v, t, graph[v].d)
	return graph[v].d
}

func main() {
	fmt.Scan(&n)
	graph = make([]node, n+1)
	for i := 1; i <= n; i++ {
		var u, k, v int
		fmt.Scan(&u, &k)
		graph[u].id = u
		// 頂点uはk個の隣接頂点を持っている
		for j := 0; j < k; j++ {
			fmt.Scan(&v)
			var t node
			t.id = v
			graph[u].adj = append(graph[u].adj, t)
		}
	}
	// fmt.Println("n", n, "graph", graph)
	seen = make([]bool, n+1)
	// t := dfs(1, 1)
	v, t := 1, 1
	done := false
	for !done {
		tt := dfs(v, t)
		done = true
		for i := range seen {
			if !seen[i] {
				done = false
				v = graph[i].id
				t = tt
				break
			}
		}
	}
	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, graph[i].v, graph[i].d)
	}
}

Python: def dfs(index):
    global count
    d[index] = count
    count += 1
    for i in field[index]:
        if d[i]:
            continue
        count = dfs(i)
    f[index] = count
    return count + 1

n = int(input())
field = [[0,0]]
for _ in range(n):
    u, k, *v = map(int, input().split())
    field.append(v)
d = [0 for _ in range(n + 1)]
f = [0 for _ in range(n + 1)]

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

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

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

# for row in A:
#     msg = ' '.join(map(str, row))
#     # print(msg)

d = [-1] * n
f = [-1] * n

t = 0

# recursive


def dfs(u):
    global t
    # print('visit:', str(u), str(t))
    t += 1
    d[u] = t
    for i in range(len(A[u])):
        if A[u][i] == 1 and d[i] == -1:
            dfs(i)
    t += 1
    f[u] = t
            


for i in range(n):
    if d[i] == -1:
        # print('start from:', str(i))
        dfs(i)


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

Python: class Node(object):
    def __init__(self, V):
        self.V = V
        self.find_time = 0
        self.finish_time = 0
        self.is_finded = False


n = int(input())
nodes = []
nodes.append(Node([]))

for i in range(n):
    data = input().split()
    V = list(map(int, data[2:]))
    V.sort(reverse = True)
    nodes.append(Node(V))

find_q = []
find_q.append(1)
cnt = 1
q_size = len(find_q)
while q_size != 0:
    #print(find_q)
    node = nodes[find_q[q_size -1]]

    if node.is_finded == False:
        node.find_time = cnt
        cnt += 1
        node.is_finded = True
        if len(node.V) == 0:
            node.finish_time = cnt
            cnt += 1
            del find_q[q_size -1]
            q_size = len(find_q)
        else:
            for x in node.V:
                if x in find_q:
                    find_q.remove(x)
                if nodes[x].finish_time == 0: 
                    find_q.append(x)
            q_size = len(find_q)

    else:   #node is finded
        node.finish_time = cnt
        cnt += 1
        del find_q[q_size -1]
        q_size = len(find_q)
        continue

for i,x in enumerate(nodes):
    if i == 0:
        continue
    print(i, x.find_time, x.finish_time)

Python: N = int(input())
edge = [[] for _ in range(N+1)]
d = [0] * (N+1)
f = [0] * (N+1)
for i in range(N):
    t = list(map(int, input().split()))
    for j in range(t[1]):
        edge[t[0]].append(t[j+2])

#print(1)
def dfs(v, t):
    if d[v] == 0:
        d[v] = t
        t += 1
    else:
        return t
    for nv in edge[v]:
        t = dfs(nv, t)
    if f[v] == 0:
        f[v] = t
        t += 1
    return t

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

Python: def dfs(u, node_info, matrix):
    # ????????????????????¨??????????????????
    colors = [0] * len(matrix)
    detect_time = [0] * len(matrix)
    finished_time = [0] * len(matrix)
    time = 1
    stack = list()
    stack.append(u)
    colors[u] = 1
    detect_time[u] = time
    while len(stack):
        for i, val in enumerate(matrix[u]):
            if val == 1 and colors[i] == 0:
                time += 1
                print('stack: ', i)
                stack.append(i)
                colors[i] = 1
                detect_time[i] = time
                u = i
                break
        else:
            time += 1
            e = stack.pop()
            colors[e] = 2
            finished_time[e] = time
            if len(stack):
                u = stack[-1]
    for i in range(len(matrix)):
        print('{} {} {}'.format(i + 1, detect_time[i], finished_time[i]))


if __name__ == '__main__':
    N = int(input())
    matrix = [[0] * N for _ in range(N)]
    color = [0] * N
    for i in matrix:
        node_info = [int(i) for i in input().split()]
        node_i = node_info[0] - 1
        if not node_info[1] == 0:
            for i in node_info[2:]:
                matrix[node_i][i - 1] = 1
    for line in matrix:
        print(line)
    dfs(0, None, matrix)

Python: n = int(input())

points = []
seen = []
find_time = []
end_time = []
for _ in range(n):
    input_text = list(map(int, input().split()))
    u, k, v_list = input_text[0], input_text[1], input_text[2:]
    seen.append(False)
    points.append(v_list)
    find_time.append(0)
    end_time.append(0)

count = [0]


def dfs(graph, v, count):
    seen[v] = True
    find_time[v] = count[0]
    for next_v in graph[v]:
        if seen[next_v - 1]:
            continue
        count[0] += 1
        dfs(graph, next_v - 1, count)
    count[0] += 1
    end_time[v] = count[0]


for index, seen_point in enumerate(seen):
    if seen_point:
        pass
    else:
        count[0] += 1
        dfs(points, index, count)
# print(find_time)
# print(end_time)


count = 1
for f, e in zip(find_time, end_time):
    print(count, f, e)
    count += 1

Python: # -*- coding: utf-8 -*-
"""
Created on Sun Jul  8 10:56:33 2018

@author: maezawa
"""
n = int(input())
adj = [[] for _ in range(n)]
d = [0 for _ in range(n)]
f = [0 for _ in range(n)]

for j in range(n):
    ain = list(map(int, input().split()))
    u = ain[0]
    k = ain[1]
    for i in range(k):
        adj[u-1].append(ain[i+2]-1)
    adj[u-1].sort()
    #print(*adj[u-1])

t = 1
stack = [0]

while stack:
    current = stack[-1]
    if d[current] == 0:
        d[current] = t
        t += 1
    flag = 0
    for k in adj[current]:
        if f[k] == 0:
            stack.append(k)
            flag = 1
            break
    if flag == 0:
        f[current] = t
        t += 1
        stack.pop()

    #print('current = {}, t = {}'.format(current, t))
    #print('stack', *stack)

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

Python: def MAIN():
    n = int(input())
    ans = [[i, 0, 0] for i in range((n + 1))]
    G = [[] for _ in range((n + 1))]
    for _ in range(n):
        u, k, *v = map(int, input().split())
        G[u] = v
    cnt = 1
    def dfs(u):
        nonlocal ans
        if ans[u][1] != 0:
            return
        nonlocal cnt
        ans[u][1] = cnt
        cnt += 1
        for v in G[u]:
            dfs(v)
        ans[u][2] = cnt
        cnt += 1
    dfs(1)
    for i in range(1, n + 1):
        print(" ".join(map(str, ans[i])))
MAIN()