Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	f         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes] = &DirectedGraphNode{}
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].f = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

var time = 0

func fillDistancesByDepthFirstSearch(g *DirectedGraph) {
	for _, u := range g.nodes[1:] {
		if !u.visited {
			dfsVisit(g, u)
		}
	}
}

func dfsVisit(g *DirectedGraph, u *DirectedGraphNode) {
	time++
	u.d = time

	u.visited = true
	for _, v := range u.adjacents {
		if !v.visited {
			v.parent = u
			dfsVisit(g, v)
		}
	}
	time++
	u.f = time
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	fillDistancesByDepthFirstSearch(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		fmt.Println(node.key, node.d, node.f)
	}
}

C++: 
#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <map>
#include <set>
#include <math.h>
using namespace std;
typedef long long int ll;
#define rep(i, a, n) for (ll i = a; i < (ll)(n); i++)
long long GCD(long long a, long long b) { return b ? GCD(b, a%b) : a; }
long long LCM(long long a, long long b)  {return a/GCD(a,b)*b;}
int n;
int graph[100][100];
int d[100];
int f[100];
int now=0;
int k[100];
bool beg[106];
void dfs(int p)
{
    
   beg[p-1]=true;
 //  cout<<“p”<< p<<endl;
   //if(d[p-1]==-1)
   d[p-1]=now;
  // cout<<“now “<<now<<endl;
   if(k[p-1]==0)
   {
       now++;
       f[p-1]=now;
   }
   else
   {
       for(int i=0;i<k[p-1];i++)
       {
           if(beg[graph[p-1][i]-1]==false)
           {
               now++;
               dfs(graph[p-1][i]);
           }
       }
       now++;
       f[p-1]=now;
   }
}
int main(){
   cin>>n;
   for(int i=0;i<n;i++)
   {
       beg[i]=false;
       d[i]=-1;
       f[i]=-1;
       int number;
       cin>>number;
       cin>>k[i];
       for(int j=0;j<k[i];j++)
           cin>>graph[i][j];
   }
   now=0;
   for(int i=0;i<n;i++)
   {
       if(beg[i]==false)
       {
           now++;
           dfs(i+1);
       }
   }
   for(int i=0;i<n;i++)
   {
       cout<<i+1<<" "<<d[i]<<" "<<f[i]<<endl;
   }
   return 0;
}

C++: #include <bits/stdc++.h>

int d[128];
int f[128];
bool c[128][128];
int n;
int t;
int checked[128];

void dfs(int i) {
  if( checked[i] ) return;
  checked[i] = true;
  t += 1;
  d[i] = t;
  for(int k = 1; k <= n; ++k) {
    if( c[i][k] ) {
      dfs(k);
    }
  }
  t += 1;
  f[i] = t;
  return;
}

int main(void) {

  for(int i = 0; i < 128; ++i) {
    for(int j = 0; j < 128; ++j) {
      c[i][j] = false;
    }
  }

  std::cin >> n;

  int u, k, v;
  for(int i = 0; i < n; ++i) {
    std::cin >> u >> k;
    for(int j = 0; j < k; ++j) {
      std::cin >> v;
      c[u][v] = true;
    }
  }

  for(int i = 1; i <= n; ++i) {
    dfs(i);
  }

  for(int i = 1; i <= n; ++i) {
    std::cout << i << " " << d[i] << " " << f[i] << std::endl;
  }
  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, Adj[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 (Adj[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++) {
			Adj[i][j] = 0;
		}
	}
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		u--;
		for (int j = 0; j < k; j++) {
			cin >> v;
			v--;
			Adj[u][v] = 1;
		}
	}
	
	dfs();
	return 0;
}

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

int a[100][100];
int n,p,q,r;
int T[100],F[100];
int Time = 0;
void dfs(int cur) {
	T[cur] = Time;
	Time += 1;
	for (int dst=0; dst < n; ++dst) {
		if(a[cur][dst] == 1 && T[dst] == -1) {
			dfs(dst);
		}
	}
	F[cur] = Time;
	Time += 1;
}

int main() {
	cin >> n;
	for (int i=0; i<n; ++i) {
		cin >> p >> q;
		T[i] = -1;
		for (int j=0; j<q; ++j) {
			cin >> r;
			a[p-1][r-1] = 1;
		}
	}
	dfs(0);
	for (int i=0; i<n; ++i) {
		cout << i+1 << " " << T[i]+1 << " " << F[i]+1 << endl;
	}
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<cmath>

#define FOR(i,a,b) for(int i=(a);i<(b);++(i))
#define REP(i,n) FOR(i,0,n)

#define dump(x) cerr << #x << " = " <<(x)<<endl;
#define debug(x) cerr << #x << " = " <<(x) << "(L" << __LINE__ << ")" << __FILE__ << endl;

using namespace std;
typedef vector<vector<int>> VVI;

VVI mat;
vector<int> d,f,color;
int tt,n;

void dfs_visit(int i){
  int v;
  color[i] = 1;
  d[i]=++tt;
  REP(v,n){
    if(mat[i][v]==0) continue;
    if(color[v]==0){
      dfs_visit(v);
    }
  }
  color[i] = 2;
  f[i] = ++tt;
}
void dfs(int n){
  tt=0;

  int i;
  REP(i,n){
    if(color[i]==0) dfs_visit(i);
  }

  REP(i,n) cout << i+1 << " " << d[i] << " " << f[i] << endl;
}

int main(void){
  int q,k,i,l;
  cin >> n;
  mat=VVI(n, vector<int>(n));
  color=d=f=vector<int>(n);
  REP(i,n){
    cin >> l; l--;
    cin >> q;
    REP(j,q){
      cin >> k; k--;
      mat[l][k]=1;
    }
  }
  dfs(n);

  return 0;
}