Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	f         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes] = &DirectedGraphNode{}
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].f = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

var time = 0

func fillDistancesByDepthFirstSearch(g *DirectedGraph) {
	for _, u := range g.nodes[1:] {
		if !u.visited {
			dfsVisit(g, u)
		}
	}
}

func dfsVisit(g *DirectedGraph, u *DirectedGraphNode) {
	time++
	u.d = time

	u.visited = true
	for _, v := range u.adjacents {
		if !v.visited {
			v.parent = u
			dfsVisit(g, v)
		}
	}
	time++
	u.f = time
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	fillDistancesByDepthFirstSearch(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		fmt.Println(node.key, node.d, node.f)
	}
}

C++: #include <bits/stdc++.h>
using namespace std;

#define N_MAX 100
#define WH 0
#define GR 1
#define BK 2

long n;
long ttime = 0;
long G[N_MAX][N_MAX] = {};
long D[N_MAX], F[N_MAX];
long color[N_MAX] = {};

void dfs_rec(long u) {
    color[u] = GR;
    ttime++;
    D[u] = ttime;
    // cout << "start time " << u << ": " << D[u] << endl;

    for (long v = 0; v < n; v++) {
        // cout << "(u, v) = (" << u << ", " << v << ")" << endl;
        if (G[u][v] == 1 && color[v] == WH) {
            dfs_rec(v);
        }
    }
    color[u] = BK;
    ttime++;
    F[u] = ttime;
    // cout << "end time " << u << ": " << F[u] << endl;
}

int main() {
    long v_from, deg_out, v_to;

    cin >> n;
    for (long i = 0; i < n; i++) {
        cin >> v_from >> deg_out;
        v_from--;
        for (long j = 0; j < deg_out; j++) {
            cin >> v_to;
            v_to--;
            G[v_from][v_to] = 1;
        }
    }

    // for (long i = 0; i < n; i++) {
    //     for (long j = 0; j < n; j++) {
    //         if (j != 0) { cout << " "; }
    //         cout << G[i][j];
    //     }
    //     cout << endl;
    // }

    for (long u = 0; u < n; u++) {
        if (color[u] == WH) {
            dfs_rec(u);
        }
    }

    for (long i = 0; i < n; i++) {
        cout << i + 1 << " " << D[i] << " " << F[i] << endl;
    }

    return 0;
}

C++: #include<iostream>
#include<stack>
using namespace std;

struct time_check {
    int find_time, end_time;
};

int G[101][101] = {0};
time_check t[101];
int elapsed = 1, n;
stack<int> S;

void dfs(int start) {
    S.push(start);
    while (! S.empty()) {
        elapsed++;
        int u = S.top();
        for (int i = 1; i <= n + 1; i++) {
            if (G[u][i] == 1 && t[i].end_time == 0) {
                t[i].find_time = elapsed;
                G[u][i] = 0;
                S.push(i);
                break;
            }
            if (i == n + 1) {
                t[u].end_time = elapsed;
                S.pop();
            }
        }
    }
}

int main() {
    for (int i = 1; i <= 100; i++) t[i].end_time = 0;

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

    t[1].find_time = 1;

    for (int i = 1; i <= n; i++) {
        if (t[i].end_time == 0) dfs(i);
    }

    for (int i = 1; i <= n; i++) {
        cout << i << " " << t[i].find_time << " " << t[i].end_time << endl;
    }

    return 0;
}

/*
#include<iostream>
#include<stack>
using namespace std;
static const int N = 100;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BRACK = 2;

int n, M[N][N];
int color[N], d[N], f[N], tt;
int nt[N];

// uに隣接するvを番号順に取得
int next(int u) {
    for (int v = nt[u]; v < n; v++) {
        nt[u] = v + 1;
        if (M[u][v]) return v;
    }
    return -1;
}

// スタックを用いた深さ優先探索
void dfs_visit(int r) {
    for (int i = 0; i < n; i++) nt[i] = 0;

    stack<int> S;
    S.push(r);
    color[r] = GRAY;
    d[r] = ++tt;

    while (! S.empty()) {
        int u = S.top();
        int v = next(u);
        if (v != -1) {
            if (color[v] == WHITE) {
                color[v] = GRAY;
                d[v] = ++tt;
                S.push(v);
            }
        } else {
            S.pop();
            color[u] = BRACK;
            f[u] = ++tt;
        }
    }
}

void dfs() {
    // 初期化
    for (int i = 0; i < n; i++) {
        color[i] = WHITE;
        nt[i] = 0;
    }
    tt = 0;

    // 未訪問のuを始点として深さ優先探索
    for (int u = 0; u < n; u++) {
        if (color[u] == WHITE) dfs_visit(u);
    }
    for (int i = 0; i < n; i++) {
        cout << i+1 << " " << d[i] << " " << f[i] << endl;
    }
}

int main() {
    int u, k, v;

    cin >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) M[i][j] = 0;
    }

    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();

    return 0;
}
*/

C++: #include <iostream>
#include "string.h"
#include "stdio.h"
using namespace std;
int n,m[107][107];
int color[107],d[107],f[107],tt;

void dfs_visit(int u)
{
	int v;
	color[u]=1;
	d[u]=++tt;
	for(v=0;v<n;v++)
	{
		if(m[u][v]==0)continue;
		if(color[v]==0)dfs_visit(v);
	}
	color[u]=2;
	f[u]=++tt;
}

void dfs()
{
	int u;
	for(u=0;u<n;u++)color[u]=0;
	tt=0;
	
	for(u=0;u<n;u++)
		if(color[u]==0)dfs_visit(u);
	for(u=0;u<n;u++)
		printf("%d %d %d\n",u+1,d[u],f[u]);
}
int main(int argc, char *argv[]) {
	int u,k,v,i,j;
	cin>>n;
	memset(m, 0, sizeof(m));
	for(i=0;i<n;i++)
	{
		scanf("%d %d",&u,&k);
		u--;
		for(j=0;j<k;j++)
		{
			scanf("%d",&v);
			v--;
			m[u][v]=1;
		}
	}
	
	dfs();
	
	return 0;
}

C++: #include <iostream>
using namespace std;

int n, t = 0;
int v[100][100];
int d[100], f[100], r[101];

void st(int id) {
	if (!r[id]) {
		r[id]++;
		d[id - 1] = ++t;
		for (int i = 0; i < n; i++)
			if (v[id - 1][i])
				st(i + 1);
		f[id - 1] = ++t;
	}
}

int main()
{
	cin >> n;

	for (int i = 0; i < n; i++) {
		int u, k, s;

		cin >> u >> k;

		for (int j = 0; j < k; j++) {
			cin >> s;
			v[u - 1][s - 1] = 1;
		}
	}

	st(1);

	for (int i = 0; i < n; i++)
		cout << i + 1 << " " << d[i] << " " << f[i] << endl;

	return 0;
}