Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const N = 100

const (
	WHITE = iota
	GRAY
	BLACK
)

type Graph struct {
	M               [N][N]int
	color, d, f, nt [N]int
	tt              int
}

func (g *Graph) next(u, n int) int {
	for v := g.nt[u]; v < n; v++ {
		g.nt[u] = v + 1
		if g.M[u][v] != 0 {
			return v
		}
	}
	return -1
}

func (g *Graph) dfsVisit(r, n int) {
	var S []int
	S = append([]int{r}, S...)
	g.color[r] = GRAY
	g.tt++
	g.d[r] = g.tt

	for len(S) != 0 {
		u := S[0]
		v := g.next(u, n)
		if v == -1 {
			S = S[1:]
			g.color[u] = BLACK
			g.tt++
			g.f[u] = g.tt
			continue
		}

		if g.color[v] != WHITE {
			continue
		}

		g.color[v] = GRAY
		g.tt++
		g.d[v] = g.tt
		S = append([]int{v}, S...)
	}
}

func (g *Graph) dfs(n int) string {
	for i := 0; i < n; i++ {
		g.color[i] = WHITE
	}
	g.tt = 0

	for u := 0; u < n; u++ {
		if g.color[u] == WHITE {
			g.dfsVisit(u, n)
		}
	}

	var out bytes.Buffer
	for i := 0; i < n; i++ {
		out.WriteString(fmt.Sprintf("%d %d %d\n", i+1, g.d[i], g.f[i]))
	}

	return strings.TrimRight(out.String(), "\n")
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	var g Graph
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		u--
		for j := 0; j < k; j++ {
			sc.Scan()
			v, _ := strconv.Atoi(sc.Text())
			v--
			g.M[u][v] = 1
		}
	}

	return g.dfs(n)
}

func main() {
	fmt.Println(answer(os.Stdin))
}

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

using namespace std;

const int edge = 1;
const int no_edge = 0;
const int no_time = -1;
const int no_label = -1;


// return finished time
int depth_search(
  int started_label,
  int current_time,
  vector<vector<int>> matrices_graph,
  vector<int>& discovered_times,
  vector<int>& finished_times
) {
  stack<int> visited_stack;
  int vertex_num = matrices_graph.size();
  visited_stack.push(started_label);
  discovered_times[started_label -1] = ++current_time;

  while(!visited_stack.empty()) {
    int current_label = visited_stack.top();

    // find no visited vertex
    int no_visited_label = no_label;
    for(int i = 0; i < vertex_num; i++) {
      if(matrices_graph[current_label - 1][i] != edge) {
        continue;
      }
      if(discovered_times[i] != no_time) {
        continue;
      }
      no_visited_label = i + 1;
      break;
    }

    if(no_visited_label != no_label) {
      visited_stack.push(no_visited_label);
      discovered_times[no_visited_label - 1] = ++current_time;
    } else {
      int finished_label = visited_stack.top();
      visited_stack.pop();

      finished_times[finished_label - 1] = ++current_time;
    }
  }

  return current_time;
}

int main() {
  int vertex_num;
  cin >> vertex_num;
  vector<vector<int>> matrices_graph(
    vertex_num,
    vector<int>(vertex_num, 0)
  );


  // set adjacency matrices graph
  for(int i = 0; i < vertex_num; i++) {
    int vertex_label;
    int adjacency_num;
    cin >> vertex_label >> adjacency_num;

    for(int j = 0; j < adjacency_num; j++) {
      int adjacency_label;
      cin >> adjacency_label;
      matrices_graph[vertex_label -1][adjacency_label - 1] = edge;
    }
  }

  vector<int> discovered_times(vertex_num, no_time);
  vector<int> finished_times(vertex_num, no_time);

  int current_time = 0;
  for(int i = 0; i <vertex_num; i++) {
    if(discovered_times[i] == no_time) {
      int started_label = i + 1;
      current_time = depth_search(
        started_label,
        current_time,
        matrices_graph,
        discovered_times,
        finished_times
      );
    }
  }

  for(int i = 0; i < vertex_num; i++) {
    cout << i + 1 << ' ' <<  discovered_times[i] << ' ' << finished_times[i] << endl;
  }
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#include<queue>
#include<map>
#include<stack>
#include<cmath>
#include<iomanip>
#include<set>
#include<numeric>
#include<sstream>
#include<random>
using namespace std;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rrep(i, st, n) for (int i = st; i < n; ++i)
using pii = pair<int, int>;
const int inf = 1e9 + 7;
int dy[] = {0, 0, -1, 1};
int dx[] = {1, -1, 0, 0};

int n;
int table[101][101];
int reached[101];
int back[101];
int bn = 1;
int cost = 1;
void dfs(int now) {
    //cout << bn << " " << now << " " << cost << endl;
    rrep(i, 1, n + 1) {
        if (table[now][i] == 1 && reached[i] == 0) {
            cost++;
            reached[i] = cost;
            bn = now;
            dfs(i);
        }
    }
    
    cost++;
    //cout << now << " " << cost << endl;
    back[now] = cost;
    return;
}
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> n;
    rep(i, n + 1) rep(j, n + 1) table[i][j] = 0;
    rep(j, n) {
        int u, k; cin >> u >> k;
        int v;
        rep(l, k) {
            cin >> v;
            table[u][v] = 1;
        }
    }
    reached[1] = 1;
    dfs(1);
    rrep(i, 2, n + 1) {
        if (reached[i] == 0) {
            reached[i] = ++cost;
            dfs(i);
        }
    }
    rrep(i, 1, n + 1) cout << i << " " << reached[i] << " " << back[i] << endl;
    
}

C++: // C++ 14
#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <algorithm>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <unordered_map>
#include <math.h>

#define ll long long
#define Int ll
#define loop(__x, __start, __end) for(Int __x = __start; __x < __end; __x++)
#define loopdown(__x, __start, __end) for(Int __x = __start; __x > __end; __x--)
#define rep(__n) for(Int __x = 0; __x < __n; __x++)
#define span(__a,__x,__y) __a.begin()+__x,__a.begin()+__y
#define span_all(__a) __a.begin(),__a.end()
#define len(__x) (__x.size())
#define last(__x) (__x[__x.size()-1])

using namespace std;

struct Point {
  Int x, y;
  Point(Int x, Int y): x(x), y(y) {}
  Point(): x(0), y(0) {}

  bool operator< (const Point &p1) const {
    return x < p1.x && y < p1.y;
  }
};
ostream & operator << (ostream & out, Point const & v) {
  out << "Point(" << v.x << ", " << v.y << ')';
  return out;
}

istream & operator >> (istream & in, Point & v) {
  Int x, y;
  in >> x; in >> y; v.x = x; v.y = y;
  return in;
}

// Geometry

#define EPS 0.0000000001

class Vector2 {
public:
  double x, y;
  
  Vector2(double x = 0, double y = 0): x(x), y(y) {}
  
  Vector2 operator + (Vector2 v) { return Vector2(x + v.x, y + v.y); }
  Vector2 operator - (Vector2 v) { return Vector2(x - v.x, y - v.y); }
  Vector2 operator * (double k) { return Vector2(x * k, y * k); }
  Vector2 operator / (double k) { return Vector2(x / k, y / k); }
  
  double length() { return sqrt(norm()); }
  double norm() { return x * x + y * y; }
  double dot (Vector2 v) { return x * v.x + y * v.y; }
  double cross (Vector2 v) { return x * v.y - y * v.x; }
  
  bool operator < (const Vector2 &v) const {
    return x != v.x ? x < v.x : y < v.y;
  }
  
  bool operator == (const Vector2 &v) const {
    return fabs(x - v.x) < EPS && fabs(y - v.y) < EPS;
  }
};

ostream & operator << (ostream & out, Vector2 const & v) { 
  out<< "Vector2(" << v.x << ", " << v.y << ')';
  return out;
}

istream & operator >> (istream & in, Vector2 & v) { 
  double x, y;
  in >> x;
  in >> y;
  v.x = x;
  v.y = y;
  return in;
}

Int N, t = 1;
vector<vector<Int> > G(101);
vector<Int> D(101, -1), F(101, -1);

void input() {
  cin >> N;
  Int v, c, u;
  rep(N) {
    cin >> v >> c; v--;
    rep(c) {
      cin >> u; u--;
      G.at(v).push_back(u);
    }
  }
}

void dfs(Int n) {
  if (D.at(n) >= 0) return;
  D.at(n) = t++;
  for (auto v: G.at(n)) {
    dfs(v);
  }
  F.at(n) = t++;
  return;
}

void solve() {
  for (int i=0; i<N; i++) dfs(i);
  for (int i=0; i<N; i++) {
    cout << (i+1) << " " << D.at(i) << " " << F.at(i) << endl;
  }
}

int main() {
  input();
  solve();
  return 0;
}