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 <bits/stdc++.h>
using namespace std;

vector<vector<int>> g;
vector<int> f,d;
vector<bool> seen;
int tim = 1;

void dfs(int now){
  seen[now] = true;
  d[now] = tim;
  tim++;
  
  for(int next: g[now]){
    if(seen[next]){
      continue;
    }
    dfs(next);
  }
  f[now] = tim;
  tim++;
}

int main(){
  int n;
  cin >> n;
  g = vector<vector<int>>(n);
  f = d = vector<int>(n);
  seen = vector<bool>(n,false);

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

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

C++: #include<bits/stdc++.h>
#define ll long long int
#define FOR(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n)

using namespace std;

static const int N = 100;
static const int white = 0;
static const int gray = 1;
static const int black = 2;

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

void dfs_visit(int u) {
  color[u] = gray;
  d[u] = ++tt;
  REP(v, n) {
    if ( M[u][v] == 0) continue;
    if ( color[v] == white ) {
      dfs_visit(v);
    }
  }
  color[u] = black;
  f[u] = ++tt;
}

void dfs() {
  REP(u, n) color[u] = white;
  tt = 0;

  REP(u, n) {
    if ( color[u] == white ) dfs_visit(u);
  }
  REP(u, n) {
    cout << u + 1 << " " << d[u] << " " << f[u] << endl;
  }
}

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

  cin >> n;
  REP(i, n) {
    REP(j, n) {
      M[i][j] = 0;
    }
  }

  REP(i, n) {
    cin >> u >> k;
    u--;
    REP(j, k) {
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  dfs();

  return 0;
}

C++: #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 BLACK = 2;

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

int next(int u){
	for(int v = nt[u]; v < n; v++) {
		nt[u] = v + 1;
		if(M[u][v] = 1) return v;
	}
	return -1;
}

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 {
		   color[v] = BLACK;
		   S.pop();
		   f[v] = ++tt;
		}
	} 
}


void dfs() {
	for(int i = 0; i < n; i++) {
	     color[i] = WHITE;
	}	
	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 n, k , u, v;
	cin >> n;
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < n; j++) {
			M[i][j] = 0;
		}
	}
	cin >> k >> u;
	u--;
	for(int i = 0; i < k; i++) {
	    cin >> v;
	    v--;
		M[u][v] = 1; 
	}
	dfs();
	return 0;
}

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

static const int N = 100;
static const int white = 0;
static const int gray = 1;
static const int black = 2;

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

int nt[N];

int next(int u) {
  for (int v = nt[u]; v < n; v++) {
    nt[u] = v + 1;
    if (M[u][v]) return v;
  }
  return -1;
};

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] = black;
      f[u] = ++tt;
    }
  }
};

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

  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 <bits/stdc++.h>
using namespace std;
#ifdef ENABLE_DEBUG_OUTPUT
#define DEBUG_LOG(s) cout << s << endl;
#else
#define DEBUG_LOG(s) void();
#endif

int t = 1;
vector<vector<bool>> g;
vector<int> d;
vector<int> f;

void dfs(const int s) {
    if(d[s] != -1) return;
    d[s] = t++;

    for (auto i = 0; i < (int)g[s].size(); i++) {
        if(g[s][i]) dfs(i);
    }

    f[s] = t++;
}

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

    g.assign(n, vector<bool>(n, false));
    for (auto i = 0; i < n; i++) {
        int u, k; cin >> u >> k;
        for (auto j = 0; j < k; j++) {
            int v; cin >> v;
            g[u - 1][v - 1] = true;
        }
    }

    d.assign(n, -1);
    f.assign(n, -1);
    for (auto i = 0; i < n; i++) {
        if(d[i] == -1) dfs(i);
    }

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

    return 0;
}