Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	firstVisitAt int
	finishVisitAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		firstVisitAt: 0,
		finishVisitAt: 0,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.firstVisitAt > 0
}

func dfs(currentId vertexId, timestamp int, vertices []vertex) int {
	currentVertex := &vertices[currentId-1]
	if currentVertex.isVisited() {
		return timestamp
	}
	timestamp = timestamp + 1
	currentVertex.firstVisitAt = timestamp
	for _, adjId := range currentVertex.adjs {
		timestamp = dfs(adjId, timestamp, vertices)
	}
	timestamp = timestamp + 1
	currentVertex.finishVisitAt = timestamp
	return timestamp
}

func solveDfs(vertices []vertex) {
	timestamp := 0
	for {
		vid := vertexId(-1)
		for i := 0; i < len(vertices); i++ {
			if !vertices[i].isVisited() {
				vid = vertexId(i+1)
				break
			}
		}
		if vid > 0 {
			timestamp = dfs(vid, timestamp, vertices)
		} else {
			break
		}
	}
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveDfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d %d\n", vertices[i].id, vertices[i].firstVisitAt, vertices[i].finishVisitAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

C++: //#include <bits/stdc++.h>
#include<iostream>
#include<stack>
#define MAX 100
#define BLACK 2
#define WHITE 0
#define GRAY 1
using namespace std;

void dfsInit();
void dfs(int);
int next(int);

int n,A[MAX][MAX];
int color[MAX],d[MAX],f[MAX],nt[MAX];
int time1;
int main(){
  int i,j,u,v,k;
  cin >> n;
  for(i = 0; i < n; i++){
    for(j = 0; j< n; j++){
      A[i][j] = 0;
    }
  }
  for(i = 0; i < n; i++){
    cin >> u;
    cin >> k;
    u = u-1;
    for(j = 0; j < n; j++){
      cin >> v;
      v = v-1;
      A[u][v] = 1;
    }
  }
  dfsInit();
  return 0;
}

void dfsInit(){
  for(int i = 0; i < n; i++){
    color[i] = WHITE;
    nt[i] = 0;
  }
  time1 = 0;
  for(int u = 0; u < n; u++){
    if(color[u] == WHITE){
      dfs(u);
    }
  }
  for(int i = 0; i < n; i++){
    //printf("%d %d %d\n",i+1,d[i],f[i]);
    cout << i+1 << " " << d[i] << " " << f[i] << endl;
  }
}

int next(int u){
  int v;
  for(v = nt[u]; v < n; v++){
    nt[u] = v+1;
    if(0 < A[u][v]){
      return v;
    }
  }
  return -1;
}
void dfs(int u){
  for(int i = 0; i < n; i++){
    nt[i] = 0;
  }
  stack<int> S;
  S.push(u);
  color[u] = GRAY;
  d[u] = ++time1;
  while(!S.empty()){
    int r = S.top();
    int v = next(u);
    if(v != -1){
      if(color[v] == WHITE){
        color[v] = GRAY;
        d[v] = ++time1;
        S.push(v);
      }
    }
    else{
      S.top();
      color[r] = BLACK;
      f[r] = ++time1;
    }
  }
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <utility>
#include <iostream>
#include <algorithm>
#include <functional>
#include <unordered_map>
#include <unordered_set>

using namespace std;

#define ll long long
#define ull unsigned long long
#define INF (1 << 30)
#define LLINF (1LL << 62)
#define MOD7 1000000007
#define MOD9 1000000009
#define eps 1e-9
#define P pair<int, int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pul pair<ull, ull>
#define all(a) (a).begin(), (a).end()
#define FOR(i,a,b) for (int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);--i)
#define REP(i,n) for (int i=0;i<(n);++i)
#define RREP(i,n) for (int i=(n)-1;i>=0;--i)

void YES() { cout << "YES\n"; }
void NO() { cout << "NO\n"; }
void Yes() { cout << "Yes\n"; }
void No() { cout << "No\n"; }
void yes() { cout << "yes" << endl; }
void no() { cout << "no" << endl; }

template<class T>
class DirectedGraph {
public:
	class Edge {
	public:
		int to;
		T cost;

		Edge(int t, T c) : to(t), cost(c) {}
	};

	vector<vector<Edge>> G;
	vector<int> visit;
	vector<pii> stamp{ 0 };
	int V;

	DirectedGraph(int n = 0) {
		resize(n);
	}

	void resize(int n) {
		V = n;
		G.resize(n);
		visit.resize(n);
		stamp.resize(n);
	}

	void addEdge(int from, int to, T cost = 0) {
		int v = max(from, to);
		if (v >= V)
			resize(v + 1);
		G[from].push_back(Edge(to, cost));
	}

	int t = 1;
	void dfs(int s) {
		if (stamp[s].first == 0)
			stamp[s].first = t++;
		else
			return;

		for (int i = 0; i < G[s].size(); ++i) {
			dfs(G[s][i].to);
		}
		stamp[s].second = t++;
	}

	int bfs() {

	}
};

int main() {
	DirectedGraph<int> g;
	int n, id, k, to;
	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> id >> k;
		while (k--) {
			cin >> to;
			g.addEdge(id, to);
		}
	}

	for (int i = 1; i <= n; ++i) {
		g.dfs(i);
	}
	for (int i = 1; i <= n; ++i) {
		cout << i << " " << g.stamp[i].first << " " << g.stamp[i].second << endl;
	}

	return 0;
}