Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)
	g := make([][]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}
	}

	d := make([]int, n+1)
	f := make([]int, n+1)
	t := 1
	for i := 1; i <= n; i++ {
		t = dfs(&g, &d, &f, i, t)
	}

	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d %d\n", i, d[i], f[i])
	}
}

func dfs(g *[][]int, d *[]int, f *[]int, id int, t int) int {
	if (*d)[id] > 0 {
		return t
	}
	(*d)[id] = t
	t += 1
	for i := 0; i < len((*g)[id]); i++ {
		t = dfs(g, d, f, (*g)[id][i], t)
	}
	(*f)[id] = t
	return t+1
}

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

typedef long long ll;
typedef vector<long long> vll;
typedef vector<int> vi;
typedef pair<int, int> pi;

#define yes "Yes"
#define yse "Yes"
#define no "No"

#define pb push_back
#define mp make_pair

#define NIL -1

#define list_itr list<ll>::iterator

#define rep(i, l, n) for (int i = (l); i < n; i++)
#define rep_cs(i, l, n) for (int i = (l); i <= n; i++)
#define rep_d(j, n) for (int j = n; j >= 0; j--)
#define rep_d_op(j, n, a) for (int j = n; j >= a; j--)

template <class T>
inline bool chmax(T &a, T b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
inline bool chmin(T &a, T b)
{
    if (a > b)
    {
        a = b;
        return 1;
    }
    return 0;
}

const int MOD = 1000000007;
const vector<int> dx = {1, 0};
const vector<int> dy = {0, 1};
const ll INF = 1LL << 60;

// int max = *std::max_element(v.begin(), v.end());
// int sum = accumulate(v, v + v.size(), 0);

int GCD(int a, int b) { return b ? GCD(b, a % b) : a; }

using Graph = vector<vector<int>>;
Graph G;
vector<bool> seen;

bool binary_search(int a[], int n, int key)
{
    int l = 0;
    int r = n;
    int middle;
    while (l < r)
    {
        middle = (l + r) / 2;
        if (key == a[middle])
        {
            return true;
        }

        if (key > a[middle])
        {
            l = middle + 1;
        }
        else if (key < a[middle])
        {
            r = middle;
        }
    }
    return false;
}

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)
{
    rep(v, nt[u], n)
    {
        nt[u] = v + 1;
        if (M[u][v])
        {
            return v;
        }
    }
    return -1;
}

void dfs_visit(int r)
{
    rep(i, 0, n)
    {
        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()
{
    rep(i, 0, n)
    {
        color[i] = WHITE;
        nt[i] = 0;
    }
    tt = 0;

    rep(u, 0, n)
    {
        if (color[u] == WHITE)
        {
            dfs_visit(u);
        }
    }

    rep(i, 0, n)
    {
        cout << i + 1 << " " << d[i] << " " << f[i] << endl;
    }
}

int main()
{
    int u, k, v;
    cin >> n;

    rep(i, 0, n)
    {
        rep(j, 0, n)
        {
            M[i][j] = 0;
        }
    }

    rep(i, 0, n)
    {
        cin >> u >> k;
        u--;
        rep(j, 0, k)
        {
            cin >> v;
            v--;
            M[u][v] = 1;
        }
    }

    dfs();
}

C++: #include <bits/stdc++.h>
using namespace std;
const int N = 101;
int v[N][N]={0};
int stt[N]={0};
int fit[N]={0};
int t=0;

void dfs(int n){
	if(stt[n]!=0) return;
	stt[n] = ++t;
	for(int i=0;i<v[n][1];i++){
		dfs(v[n][i+2]);
	}
	fit[n]=++t;
}

int main(){
	int n;
	cin >> n;
	for(int i=0;i<n;i++){
		int u,k;
		cin >> u >> k;
		v[u][0]=i+1;
		v[u][1]=k;
		for(int j=0;j<k;j++){
			int a;
			cin >> a;
			v[u][j+2]=a;
		}
	}
	for(int i=1;i<=n;i++)dfs(i);
	for(int i=1;i<n+1;i++){
		cout << i << " " <<stt[i] << " " << fit[i] << endl;
	}
    return 0;
}