Go: package main

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

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	num, _ := strconv.Atoi(sc.Text())
	nodes := make(map[int]*node)

	for i := 0; i < num; i++ {
		sc.Scan()
		id, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		nodeNum, _ := strconv.Atoi(sc.Text())
		n := node{id, make([]int, 0), 0, 0}
		for j := 0; j < nodeNum; j++ {
			sc.Scan()
			nid, _ := strconv.Atoi(sc.Text())
			n.nexts = append(n.nexts, nid)
		}
		nodes[id] = &n
	}

	s := Stack{}
	for i := 1; i < len(nodes)+1; i++ {
		if nodes[i].s != 0 {
			continue
		}
		walk(i, &nodes, s)
	}
	for i := 1; i < len(nodes)+1; i++ {
		fmt.Printf("%v %v %v\n", (*nodes[i]).id, (*nodes[i]).s, (*nodes[i]).e)
	}
}

var time int

func walk(nid int, nodes *map[int]*node, s Stack) {
	n := (*nodes)[nid]
	if n.s != 0 {
		return
	}
	time++
	n.s = time
	s.Push(n)
	for _, v := range n.nexts {
		walk(v, nodes, s)
	}
	time++
	n.e = time
}

type node struct {
	id    int
	nexts []int
	s     int
	e     int
}

// Stack is Stack
type Stack struct {
	stack []interface{}
}

// Push new value
func (stack *Stack) Push(val interface{}) {
	stack.stack = append(stack.stack, val)
}

// Pop new value
func (stack *Stack) Pop() interface{} {
	val := stack.stack[len(stack.stack)-1]
	stack.stack = stack.stack[0 : len(stack.stack)-1]
	return val
}

C++: #include <iostream>
#include <vector>

using namespace std;

struct Edge
{
	int to;
};

vector<vector<int>> DFS(vector<vector<Edge>>& G)
{
	int timecounter = 0;
	int next = 1;
	vector<vector<int>> result;
	result = vector<vector<int>>(2, vector<int>(G.size(), 0));
	vector<int> prev(G.size(),0);
	
	while(result[1][0] == 0){
		int tmp;
		if(result[0][next - 1] == 0){
			timecounter += 1;	
			result[0][next - 1] = timecounter;
		}

		if(G[next - 1].empty()){
			if(result[1][next - 1] == 0){
				timecounter +=1;
				result[1][next - 1] = timecounter;
			}
			next = prev[next - 1];
		}else{
			tmp = G[next - 1].begin()->to;
			G[next - 1].erase(G[next - 1].begin());
			prev[tmp - 1] = next;
			next = tmp;
		}
	}
	return result;
}

int main(void)
{
	int n;
	cin >> n;

	vector<vector<Edge>> AdjList(n);
	for(int i = 0; i < n; i++){
		int u, k;
		cin >> u >> k;
		for(int j = 0; j < k; j++){
			int v;
			cin >> v;
			AdjList[i].push_back(Edge{v});
		}
	}

	vector<vector<int>> timestump = DFS(AdjList);
	
	for(int i = 0; i < AdjList.size(); i++){
		cout << i + 1 << " " << timestump[0][i] << " " << timestump[1][i] << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, a, b) for (int i = a; i < b; ++i)
#define FORR(i, a, b) for (int i = b - 1; i >= a; --i)
#define SORT(v) sort(v.begin(), v.end())
#define SORTR(v) sort(v.rbegin(), v.rend())
#define REV(v) reverse(v.begin(), v.end())
#define ITER(itr, v) for (auto itr = v.begin(); itr != v.end(); ++itr)
#define LB(v, x) (lower_bound(v.begin(), v.end(), x) - v.begin())
#define UB(v, x) (upper_bound(v.begin(), v.end(), x) - v.begin())
#define SZ(v) (int)v.size()
using namespace std;
using ll = long long;
using P = pair<int, int>;

class Graph {
	int N;
	vector<vector<int>> edge;
	vector<int> d, f;

public:
	Graph(int n) : N(n), edge(n + 1), d(n + 1), f(n + 1) {
		REP(i, N) {
			add(0, i + 1);
		}
	}
	void add(int u, int v) {
		edge[u].emplace_back(v);
	}
	int dfs(int i) {
		f[i] = d[i];
		for (auto &j : edge[i]) {
			if (!d[j]) {
				d[j] = f[i] + 1;
				f[i] = dfs(j);
			}
		}
		return ++f[i];
	}
	void ans() {
		dfs(0);
		for (int i = 1; i <= N; ++i) {
			cout << i << " " << d[i] << " " << f[i] << endl;
		}
	}
};

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n;
	cin >> n;
	Graph graph(n);
	REP(x, n) {
		int u, k;
		cin >> u >> k;
		REP(y, k) {
			int v;
			cin >> v;
			graph.add(u, v);
		}
	}
	graph.ans();

	return 0;
}

C++: #include <iostream>

using namespace std;
int n,u,k,v,**M,flag[100],s_time[100],f_time[100];
void creat()
{
    cin>>n;
  M=new int*[n];
  for(int i=0;i<n;i++)
    {
      M[i]=new int[n];
      flag[i]=0;
      for(int j=0;j<n;j++)
	M[i][j]=0;
    }
  int count=0;
  while(count<n)
    {
      count++;
      cin>>u>>k;
      for(int i=0;i<k;i++)
	{
	  cin>>v;
	  M[u-1][v-1]=1;
	}
    }
    /*for(int i=0;i<n;i++){
    for(int j=0;j<n;j++)
      cout<<M[i][j]<<' ';
    cout<<endl;
  }*/
}
int Time=0;
void dfs(int cur) {
    Time += 1;
    s_time[cur]=Time;
    //cout << "visiting " << cur+1 << ' ' << time << endl;
    flag[cur]=1;
    for (int dst=0;dst<n;dst++) {
            if (M[cur][dst]&&!flag[dst]) {
                dfs(dst);
            }
    }
    Time += 1;
    f_time[cur]=Time;
}
int main()
{
    creat();
    for(int i=0;i<n;i++)
    {
        if(!flag[i])
            dfs(i);
    }
    for(int i=0;i<n;i++)
    {
        cout<<i+1<<' '<<s_time[i]<<' '<<f_time[i]<<endl;
    }
    delete M;
    return 0;
}

C++: #include<iostream>

int main(){

  int n,a;
  std::cin>>n;

  int Adj[100][100],adj[100][100]={0},find[100][2],back[100],depth[100]={0},endflag[100]={0},flag;
  int u[n],k[n],kcou=0,timenow=0,v,pred,prev;
  for(int i=0;i<n;i++){
    std::cin>>u[i];
    std::cin>>k[i];
    for(int j=0;j<k[i];j++){
      std::cin>>Adj[i][j];
    }
  }
	
	/*
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
    	std::cout<<Adj[i][j]<<" ";
    }
  	std::cout<<"\n";
  }*/
	
	v=0;

	while(timenow<n*2){
		flag=0;
		//std::cout<<find[v][0]<<" "<<find[v][1];
		if(find[v][0]==NULL){
			timenow++;
			find[v][0]=timenow;
			flag=1;
			//std::cout<<flag<<" 1";
		}else if(find[v][1]==NULL){
			if(endflag[v]==1){
				timenow++;
				find[v][1]=timenow;
				flag=2;
			}
			//std::cout<<flag<<" 2";
		}else{
			v=back[v];
			flag=3;
			//std::cout<<flag<<" 0";
		}

		if(flag==0){
			pred=depth[v];
			depth[v]++;
			prev=v;
			v=Adj[v][pred]-1;
			back[v]=prev;
			//std::cout<<flag<<"\n";
		}else if(flag==1){
			if(endflag[v]==1){
				depth[v]++;
			}else{
				pred=depth[v];
				depth[v]++;
				prev=v;
				v=Adj[v][pred]-1;
				back[v]=prev;
				//std::cout<<v<<"\n";
			}
		}else if(flag==2){
			v=back[v];
			//std::cout<<flag<<"\n";
		}
		if(depth[v]>k[v]-1){
			endflag[v]=1;
		}
		
	}
	
	
	
	
  for(int i=0;i<n;i++){
     std::cout<<i+1<<" "<<find[i][0]<<" ";
     std::cout<<find[i][1]<<"\n";
    //std::cout<<"\n";
  }

  return 0;
}

C++: #include<iostream>
using namespace std;
#define max 100

int aa[max][max];
int n;
int d[max];
int f[max];
int color[max];
int tt = 0;
int p[max];

void dfscount(int u) {
	color[u - 1] = 1;
	int x = -1;
	for (int i = n-1; i >= 0; i--) {
		if (aa[u - 1][i] == 1 && color[i] == 0) x = i + 1;
	}
	if (x == -1) {
		f[u - 1] = ++tt;
		color[u - 1] = 2;
		if (p[u - 1] == -1) {
			for (int i = 0; i < n; i++) {
				if (color[i] != 2) {
					d[i] = ++tt;
					dfscount(i + 1);
				}
			}
			return;
		}
		dfscount(p[u - 1]);
	}
	else {
		d[x - 1] = ++tt;
		p[x - 1] = u;
		dfscount(x);
	}
}

void dfs() {
	d[0] = ++tt;

	for (int i = 0; i < n; i++) {
		color[i] = 0;
		p[i] = -1;
	}

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

int main()
{
	cin >> n;

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			aa[i][j] = 0;
		}
	}
	for (int i = 0; i < n; i++) {
		int num;
		cin >> num;
		int num1;
		cin >> num1;
		for (int j = 0; j < num1; j++) {
			int x;
			cin >> x;
			aa[num - 1][x - 1] = 1;
		}
	}

	dfs();

	return 0;
}