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;

void dfs(vector<vector<int> > &G, vector<bool> &seen, vector<int> &d, vector<int> &f, int v, int &t) {
    seen[v] = true;
    d[v] = ++t;
    for (int i = 0; i < G[v].size(); i++) {
        if (seen[G[v][i]]) continue;
        dfs(G, seen, d, f, G[v][i], t);
    }
    f[v] = ++t;
}

void print(int n, vector<int> &d, vector<int> &f) {
    for (int i = 0; i < n; i++) {
        cout << i + 1 << " " << d[i] << " " << f[i] << endl;
    }
}

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

    vector<bool> seen(n, false);
    vector<int> d(n), f(n);
    int t = 0;
    for (int i = 0; i < n; i++) {
        if (seen[i]) continue;
        dfs(G, seen, d, f, i, t);
    }
    print(n, d, f);

    return 0;
}

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

const int MAX_N = 110;
int G[MAX_N][MAX_N];
int D[MAX_N], F[MAX_N], V[MAX_N];

void dfs(int u, int n, int& count) {
  int i;
  V[u] = 1;
  D[u] = ++count;
  for (i = 0; i < n; ++i) {
    if (G[u][i] && !V[i]) {
      dfs(i, n, count);
    }
  }
  F[u] = ++count;
}

int main() {
  int i, j, u, k, v, n, count;
  
  cin >> n;

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

  count = 0;
  for (i = 0; i < n; ++i) {
    if (!V[i]) dfs(i,n,count);
  }

  for (i = 0; i < n; ++i) {
    cout << i + 1 << ' ' << D[i] << ' ' << F[i] << '\n';
  }

  return 0;
}

C++: #include <bits/stdc++.h>
#define MAX 105
#define INF (1<<30)
//#define EZPZ_LEMON_SQUEENZ
using namespace std;

vector<int> M[MAX];
stack<int> s;
int states[MAX][2];
bool vis[MAX];
int n, t;

void dfs(int index)
{
	if (index == n + 1) return;
	vis[index] = true;
	for (int i = 0; i < M[index].size(); i++)
	{
		if (!vis[M[index][i]]) {
			states[M[index][i]][0] = t++;
			dfs(M[index][i]);
			states[M[index][i]][1] = t++;
		}
	}
}

int main()
{
#ifdef EZPZ_LEMON_SQUEENZ
	freopen("D:\\in.txt", "r", stdin);
	freopen("D:\\out.txt", "w", stdout);
#endif
	ios::sync_with_stdio(false);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		int b, nn, e;
		cin >> b >> nn;
		for (int j = 1; j <= nn; j++) {
			cin >> e;
			M[b].push_back(e);
		}
	}
	t = 1;
	for (int i = 1; i <= n; i++)
	{
		if (!vis[i]) {
			states[i][0] = t++;
			dfs(i);
			states[i][1] = t++;
		}
	}
	for (int i = 1; i <= n; i++) cout << i << " " << states[i][0] << " " << states[i][1] << endl;
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> P;
typedef pair<ll, ll> Pll;
#define debug(var)  do{std::cout << #var << " : ";view(var);}while(0)
template<typename T> void view(T e){std::cout << e << std::endl;}
template<typename T> void view(const std::vector<T>& v){for(const auto& e : v){ std::cout << e << " "; } std::cout << std::endl;}
template<typename T> void view(const std::vector<std::vector<T> >& vv){ for(const auto& v : vv){ view(v); } }
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

const int MOD = 1000000007;
const int INF = 1e9;

const int mod = 1000000007;
const int inf = 1e9;
#define PI acos(-1);
int dx[4] = {1,-1,0,0};
int dy[4] = {0,0,1,-1};
int ddx[8] = {1,1,1,-1,-1,-1,0,0};
int ddy[8] = {0,1,-1,0,1,-1,1,-1};

const int mxN = 102;
vector<int> adj[mxN], in(mxN, -1), out(mxN, -1);
int t = 0;

void dfs(int i) {
    t++;
    in[i] = t;
    for(auto v: adj[i]) {
        if(in[v]==-1) {
            dfs(v);
        }
    }
    t++;
    out[i] = t;
}

int main(){
    int n;
    cin >> n;
    for(int i = 0; i < n; i++) {
        int v, k;
        cin >> v >> k;
        for(int j = 0; j < k; j++) {
            int a;
            cin >> a;
            a--;
            adj[i].push_back(a);
        }
    }
    for(int i = 0; i < n; i++) {
        if(in[i] == -1) dfs(i);
    }
    for(int i = 0; i < n; i++) {
        cout << i+1 << " " << in[i] << " " << out[i] << endl;
    }
}

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


using namespace std;

int timecount = 0;

void dfs(int cur, int u, bool* visited, int* timearray, int* timearray_end, unordered_map<int, vector<int> > mymap);

int main(){
  int u, i, id, k, j;
  cin >> u;
  unordered_map<int, vector<int> > mymap;

  for (i = 0; i < u; ++i){
    cin >> id >> k;
    vector<int> points;
    for (j = 0; j < k; ++j){
      int a;
      cin >> a;
      points.push_back(a);
    }
    mymap[id] = points;
  }
  
  bool visited[u+1];
  for (j = 1; j <= u; ++j){
    visited[j] = false;
  }
  visited[1] = true;

  int timearray[u+1];
  for (j = 1; j <= u; ++j){
    timearray[j] = 0;
  }
  int timearray_end[u+1];
  for (j = 1; j <= u; ++j){
    timearray_end[j] = 0;
  }

  dfs(1, u, visited, timearray, timearray_end, mymap);

  for (j = 1; j <= u; ++j){
    cout << j << " " << timearray[j] << " " << timearray_end[j]<< endl;
  }

}

void dfs(int cur, int u, bool* visited, int* timearray, int* timearray_end, unordered_map<int, vector<int> > mymap){
  timecount++;
  timearray[cur] = timecount;

  for(int i = 1; i <= u; ++i){
    
    if((i!=cur)&&(find(mymap[cur].begin(), mymap[cur].end(), i) != mymap[cur].end())&&(!visited[i])){
      visited[i] = true;
      dfs(i, u, visited, timearray, timearray_end, mymap);
    }
  }
  timecount++;

  timearray_end[cur] = timecount;
}

C++: #include<bits/stdc++.h>
//cout<<setprecision(1)<<fixed<<endl;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int MAX_N=100000;
const int INF = 0x3f3f3f3f;
#define eps 1e-7
//#define Kongxiangzhouye
int n;
int a[123][123];
int st[123];
int ed[123];
int now;
void dfs(int local){
	st[local]=now++;
	for(int i=1;i<=n;i++){
		if(a[local][i]){
			if(st[i]==0){
				dfs(i);
			}
		}
	}
	ed[local]=now++;
}
int main(){
	ios::sync_with_stdio(false);
	while(cin>>n){
		memset(a,0,sizeof(a));
		memset(st,0,sizeof(st));
		memset(ed,0,sizeof(ed));
		for(int i=0;i<n;i++){
			int t,m;
			cin>>t>>m;
			for(int i=0;i<m;i++){
				int te;
				cin>>te;
				a[t][te]=1;
			}
			now=1;
		}
		for(int i=1;i<=n;i++){
			if(!st[i])
				dfs(i);
		}
		for(int i=1;i<=n;i++){
			cout<<i<<" "<<st[i]<<" "<<ed[i]<<endl;
		}
	}
	return 0;
}


//