Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve(parseProblem())
}

type graph struct {
	size  int
	edges [][]int
}

func parseProblem() *graph {
	n := scanInt(sc)
	g := &graph{
		size:  n,
		edges: make([][]int, n),
	}
	for i := 0; i < g.size; i++ {
		_ = scanInt(sc)
		k := scanInt(sc)
		g.edges[i] = make([]int, k)
		for j := 0; j < k; j++ {
			g.edges[i][j] = scanInt(sc) - 1
		}
	}
	return g
}

func resolve(g *graph) {
	ds := make([]int, g.size)
	fs := make([]int, g.size)
	time := 0
	for i := 0; i < len(ds); i++ {
		if ds[i] == 0 {
			time++
			time = _dfs(ds, fs, time, g, i)
		}
	}
	for i := 0; i < len(ds); i++ {
		fmt.Println(i+1, ds[i], fs[i])
	}
	return
}

func _dfs(ds, fs []int, time int, g *graph, idx int) int {
	ds[idx] = time
	for _, next := range g.edges[idx] {
		if ds[next] > 0 {
			continue
		}
		time++
		time = _dfs(ds, fs, time, g, next)
	}
	time++
	fs[idx] = time
	return time
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: #include <iostream>
#include<stdio.h>
#include<stack>

#define MAX 100
#define WHITE 1
#define GRAY 2
#define BLACK 3

using namespace std;

int color[MAX], d[MAX], f[MAX];
int n, A[MAX][MAX];
int tt = 0;

void dfs_visit_1(int u) { //???????????°
    color[u] = GRAY;
    d[u] = ++tt;
    for(int v = 0; v < n; v++) {
        if(A[u][v] == 0) continue;
        if(color[v] == WHITE) dfs_visit_1(v);
    }
    color[u] = BLACK;
    f[u] = ++tt;
}

void dfs_1() { // ???????????°
    for(int i = 0; i < n; i++) {
        color[i] = WHITE;
    }
    tt = 0;
    for(int i = 0; i < n; i++) {
        if(color[i] == WHITE) dfs_visit_1(i);
    }

    for(int i = 0; i < n; i++) {
        printf("%d %d %d\n", i+1, d[i], f[i]);
    }

}

int next(int u) {
    for(int v = 0; v < n; v++) {
        if(A[u][v] == 1) {
            /*
            if(color[v] == WHITE) return v;
            else if(color[v] == BLACK) return -1;
            else if(color[v] == GRAY) continue;
            */
            return v;
        }
    }
    return -1;
}

void dfs_visit_2(int u) {
    color[u] = GRAY;
    d[u] = ++tt;
    stack<int> S;
    S.push(u);

    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;
        }
    }
}


int main()
{
    int u, k, v;
    scanf("%d",&n);

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


    /*
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            printf("%d", A[i][j]);
            if(j != n-1) printf(" ");
        }
        printf("\n");
    }
    */

    for(int i = 0; i < n; i++) {
        color[i] = WHITE;
    }
    dfs_visit_1(0);
    for(int i = 0; i < n; i++) {
        printf("%d %d %d\n", i+1, d[i], f[i]);
    }

    return 0;
}

C++: #include <bits/stdc++.h>
typedef long long ll;
typedef long double ld;
#define rep(i,n) for(ll i=0;i<(n);i++)
#define repr(i,n) for(ll i=(n-1);i>=0;i--)
#define all(x) x.begin(),x.end()
#define br cout << "\n";
using namespace std;
const long long INF = 1e10;
const long long MOD = 1e9+7;
using Graph = vector<vector<ll>>;
using pll = pair<ll, ll>;
template<class T> inline bool chmin(T &a, T b) { if(a > b){ a = b; return true;} return false;}
template<class T> inline bool chmax(T &a, T b) { if(a < b){ a = b; return true;} return false;}

// 0 false, 1 true 
// string to int : -48
// a to A : -32
// ceil(a)  1.2->2.0
// c++17	g++ -std=c++17 a.cpp

ll n;
vector<vector<ll>> to(n);
vector<bool> seen(n);
vector<ll> d(n);
vector<ll> f(n);

ll dfs(ll node, ll time){
    if(seen[node] == false){
        seen[node] = true;
        d[node] = time;
    }

    for(ll next : to[node]){
        if(seen[next]){
            continue;
        }else{
            time = dfs(next, time+1);
        }
    }
    time += 1;

    f[node] = time;

    return time;
}

int main() {
    std::cout << std::fixed << std::setprecision(15);
    cin >> n;
    to.resize(n);
    seen.resize(n);
    d.resize(n);
    f.resize(n);
    rep(i, n){
        ll u; cin >> u; u--;
        ll k; cin >> k;
        rep(j, k){
            ll v; cin >> v; v--;
            to[u].push_back(v);
        }
    }

    ll time = 0;
    for(ll i = 0; i < n; i++){
        if(seen[i] == false){
            time = dfs(i, time+1);
        }
    }
    

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






}