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)
	dfs(&g, &d, &f, 1, 1)

	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>
#define rep(i, n) for (int i = 0; i < (n); ++i) 
#define PI acos(-1)

using namespace std;
using ll = long long;
using P = pair<int, int>;
using LP = pair<ll, ll>;

int dfs(int t, int v, vector<vector<int>> adj, vector<P>& ts) {
    if (ts[v].first != 0) return t;

    t++;
    ts[v].first = t;
    for (auto e : adj[v]) {
        t = dfs(t, e, adj, ts);
    }
    t++;
    ts[v].second = t;
    return t;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin>>n;
    vector<vector<int>> adj(n);
    rep(i, n) {
        int u, k, v;
        cin>>u>>k; u--;
        rep(j, k) {
            cin>>v; v--;
            adj[u].push_back(v);
        }
    }

    vector<P> ts(n);
    int t = 0;
    rep(i, n) {
        if (ts[i].first != 0) continue;
        t = dfs(t, i, adj, ts);
    }
    rep(i, n) {
        cout<<i + 1<<" "<<ts[i].first<<" "<<ts[i].second<<endl;
    }
}

C++: #include<bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vs = vector<string>;
using msi = map<string, int>;
using mii = map<int, int>;
using psi = pair<string, int>;
using pii = pair<int, int>;
using vlai = valarray<int>;
#define rep(i,n) for(int i=0;i<n;i++)
#define range(i,s,n) for(int i=s;i<n;i++)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define fs first
#define sc second
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define INF 1E9
#define EPS 1E-9
#define MOD (ll)(1E9+7)
#define PI 3.1415926535897932384

template <class T>ostream &operator<<(std::ostream &o, const vector<T> &v)
{
	rep(i, v.size()) {
		o << (i > 0 ? " " : "") << v[i];
	}
	return o;
}
int n,t=0;
vvi a;
vi d;
vi f;

void Depth(int pos) {
	if (d[pos] == 0) {
		d[pos] = ++t;
	}
	rep(i, n) {
		if (a[pos][i] == 1&&d[i]==0) {
			Depth(i);
		}
	}
	if (f[pos] == 0) {
		f[pos] = ++t;
	}
}


int main() {
	cin >> n;
	a.resize(n, vi(n, 0));
	d.resize(n, 0);
	f.resize(n, 0);
	rep(i, n) {
		int num,m;
		cin >>num >>m;
		rep(i, m) {
			int tmp;
			cin >> tmp;
			a[num - 1][tmp - 1] = 1;
		}
	}
	Depth(0);
	rep(i, n) {
		if (d[i] == 0) {
			Depth(i);
		}
	}
	rep(i, n) {
		cout << i + 1 << " " << d[i] << " " << f[i] << endl;
	}
}

C++: #include<iostream>
#include<vector>
#include<utility>
using namespace std;
vector<int> l[101];
int matrix[100][100];
pair<int,int> t[101];
bool visited[101];
int tim=0;
void dfs(int cur)
{
    tim+=1;
    t[cur].first=tim;
    cerr<<"visiting "<<cur<<' '<<tim<<endl;
    visited[cur]=true;
    
    for(int i=0;i<l[cur].size();i++)
    {
        if((matrix[cur-1][l[cur][i]-1]==1)&&(visited[i]==false))
        {
            dfs(l[cur][i]);
        }
    }
    
    tim+=1;
    t[cur].second=tim;
    
    
}
int main()
{
    int n;
    cin>>n;
    for(int i=0;i<n;i++)
    {
        int u,k;
        cin>>u>>k;
        for(int j=0;j<k;j++)
        {
            int tmp;
            cin>>tmp;
            l[u].push_back(tmp);
        }
    }
    
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            matrix[i][j]=0;
        }
    }
    for(int i=1;i<n+1;i++)
    {
        visited[i]=false;
        for(int j=0;j<l[i].size();j++)
        {
            matrix[i-1][l[i][j]-1]=1;
        }
    }
    
    for(int i=1;i<n+1;i++)
    {
        if(visited[i]==false)
            dfs(i);
    }
    
    for(int i=1;i<n+1;i++)
    {
        cout<<i<<" "<<t[i].first<<" "<<t[i].second<<endl;
    }
}