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 <stack>
#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <string>
using namespace std;
#define N 100
int n, m[N][N];
int color[N], d[N], f[N], tt;
int gcd(int a, int b)
{
   if (a%b == 0)
   {
       return(b);
   }
   else
   {
       return(gcd(b, a%b));
   }
}
int mod = 1000000000 + 7;
void dfs_visit(int i){
    color[i] = 1;
    d[i] = ++tt;
    for(int j = 0; j < n; j++){
        if(m[i][j] == 0){
            continue;
        }
        if(color[j] == 0){
            dfs_visit(j);
        }
    }
    color[i] = 2;
    f[i] = ++tt;
}
void dfs(){
    for(int i = 0; i < n; i++){
        color[i] = 0;
    }
    tt = 0;
    for(int i = 0; i < n; i++){
        if(color[i] == 0){
            dfs_visit(i);
        }
    }
    for(int i = 0; i < n; i++){
        cout << i+1 << " "<<  d[i] << " " << f[i] << endl;
    }
}
int main(){
    //std::stack<int> stack;
    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();
    //cout << masu << endl;
    return 0;
}

C++: #include <cstdio>
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 2

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

//??¨???????????°?????°?????±?????????????´¢
void dfs_visit(int u){
    int v;
    color[u]=GRAY;
    //???????????????
    d[u]=++tt;
    for(v=0;v<n;v++){
        if(M[u][v]==0)
            continue;
        if(color[v]==WHITE)
            dfs_visit(v);
    }
    color[u]=BLACK;
    //????????????
    f[u]=++tt;
}

void dfs(){
    int u;
    //????§????
    for(u=0;u<n;u++)
        color[u]=WHITE;
    tt=0;
    
    for(u=0;u<n;u++)
        //??\????????????u?????????????????±?????????????´¢
        if(color[u]==WHITE)
            dfs_visit(u);
    for(u=0;u<n;u++)
        printf("%d %d %d\n",u+1,d[u],f[u]);
}

int main(){
    int u,v,k;
    
    scanf("%d",&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++){
        scanf("%d %d",&u,&k);
        u--;
        for(int j=0;j<k;j++){
            scanf("%d",&v);
            v--;
            M[u][v]=1;
        }
    }
    
    dfs();
}

C++: #include <iostream>

#include <queue>

using namespace std;

int a[101][101];

int n=0;

int found[101];

int ended[101];

int aaa(int i, int time);

int main(){

  for(int i=0; i<101; i++)

    for(int j=0; j<101; j++)

      a[i][j]=0;

  int u, k, v;

  cin>>n;

  for(int i=0; i<n; i++){

    cin>>u>>k;

    for(int j=0; j<k; j++){

      cin>>v;

      a[u][v]=1;

    }

  }

  int time=0;

  for(int i=0; i<101; i++){

    found[i]=0;

    ended[i]=0;

  }

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

    if(found[i]>0)

      continue;

    time++;

    found[i]=time;

    time=aaa(i, time);

    ended[i]=time;

  } 

  for(int i=1; i<n+1; i++)

    cout<<i<<' '<<found[i]<<' '<<ended[i]<<endl;

}

int aaa(int i, int time){

  for(int k=1; k<n+1; k++){

    if(a[i][k]==1&&found[k]==0){

      time++;

      found[k]=time;

      time=aaa(k, time);

      ended[k]=time;

    } 

  }

  time++;

  return time;

}

C++: #include <iostream>
#include <string>
#include <stack>
#include <queue>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <algorithm>

#include <cstdio>

using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define repc(i, s, n) for (int i = (s); i <= (n); i++)
#define rrep(i, n) for (int i = (n) - 1; i >= 0; i--)
#define rrepc(i, s, n) for (int i = (s); i >= (n); i--)
#define print_array(ary, size) cout << ary[0]; rep1(i, 1, size - 1) cout << ' ' << ary[i]; cout << endl;
typedef long long ll;
typedef unsigned long long ull;

#define NODE_NUM (100)

int n;
int current_time = 0;
int M[NODE_NUM][NODE_NUM] = { 0 };
int ans[NODE_NUM][2] = { 0 };
stack<int> S;

void DepthFirstSearch(int node)
{
	int current, next;

	current_time++;

	S.push(node);
	ans[node - 1][0] = current_time;

	while (!S.empty()) {
		current_time++;

		current = S.top();
		next = -1;

		rep(i, n) {
			if (M[current - 1][i] == 1 && ans[i][0] == 0) {
				next = i + 1;
				break;
			}
		}

		if (next == -1) {
			ans[current - 1][1] = current_time;
			S.pop();
		}
		else {
			ans[next - 1][0] = current_time;
			S.push(next);
		}
	}
}

int main()
{
	int u, k, v;
	bool NowSearching = true;

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

	rep(i, n) {
		if (ans[i][0] == 0) DepthFirstSearch(i + 1);
	}

	rep(i, n) {
		cout << i + 1 << ' ' << ans[i][0] << ' ' << ans[i][1] << endl;
	}

	return 0;
}

C++: #include <iostream>
#include<bits/stdc++.h>
using namespace std;
int n,a,m,b,s[100],t[100],cnt=1;
vector<int> v[100];
void dfs(int n){
    if(s[n]==0){s[n]=cnt;cnt++;}
    for(auto x:v[n]){
        if(s[x]==0)dfs(x);
    }
    if(t[n]==0){t[n]=cnt;cnt++;}
    return ;
}
int main(void){
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>a>>m;
        for(int j=0;j<m;j++){
            cin>>b;
            if(a==b)continue;
            v[a-1].push_back(b-1);
        }
    }
    for(int i=0;i<n;i++)if(s[i]==0)dfs(i);
    for(int i=0;i<n;i++){
        cout<<i+1<<" "<<s[i]<<" "<<t[i]<<endl;
    }
}