Go: package main

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

type TimeRecord struct {
	discoverTime int
	finishTime   int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	timeRecordMap := make([]TimeRecord, n)
	childrenMap := make([][]int, n)
	for i := 1; i <= n; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		timeRecordMap[node-1] = TimeRecord{-1, -1}

		childNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		childrenMap[node-1] = make([]int, childNum)
		for j := 0; j < childNum; j++ {
			child, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			childrenMap[node-1][j] = child
		}
	}

	timer := 1
	for {
		startNode := findStartNode(childrenMap, timeRecordMap)
		if startNode > 0 {
			visit(startNode, &timer, childrenMap, timeRecordMap)
		} else {
			break
		}
	}
	for k, v := range timeRecordMap {
		fmt.Printf("%d %d %d\n", k+1, v.discoverTime, v.finishTime)
	}
}

func findStartNode(childrenMap [][]int, timeRecordMap []TimeRecord) int {
	x := -1
	for node, timeRecord := range timeRecordMap {
		if timeRecord.discoverTime < 0 {
			x = node + 1
			break
		}
	}
	if x < 0 {
		return -1
	}

	found := false
	i := 0
	for i < len(childrenMap) {
		children := childrenMap[i]
		for j := 0; j < len(children); j++ {
			if children[j] == x {
				x = j + 1
				found = true
				break
			}
		}
		if found {
			i = 0
		} else {
			i++
		}
	}
	return x
}

func visit(currentNode int, timer *int, childrenMap [][]int, timeRecordMap []TimeRecord) {
	if timeRecordMap[currentNode-1].discoverTime > 0 {
		return
	}
	children := childrenMap[currentNode-1]
	timeRecordMap[currentNode-1] = TimeRecord{*timer, timeRecordMap[currentNode-1].finishTime}
	(*timer)++
	for i := 0; i < len(children); i++ {
		visit(children[i], timer, childrenMap, timeRecordMap)
	}
	timeRecordMap[currentNode-1] = TimeRecord{timeRecordMap[currentNode-1].discoverTime, *timer}
	(*timer)++
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include<iostream>
using namespace std;
#define N 100
#define WHITE 0
#define GRAY 1
#define BLACK 1

int n, M[N][N];
int color[N], s[N], f[N], ts; 

void dfs_visit(int u) {
    int v;
    color[u] = GRAY;
    s[u] = ++ts;
    for (v=0; v<n; v++) {
        if(M[u][v]==0){
            continue;
        }
        if (color[v]==WHITE) {
            dfs_visit(v);
        }
    }
    color[u] = BLACK;
    f[u] = ++ts;
}

void dfs() {
    int u;
    for (u=0; u<n; u++) {
        color[u] = WHITE;
    }
    ts = 0;
    //for (u=0; u<n; u++) {
    //    if (color[u]==WHITE){
            dfs_visit(0);
    //    }
    //}
    for (u=0; u<n; u++) {
        printf("%d %d %d\n", u+1, s[u], f[u]);
    }
}

int main() {
    int u, k, tmp;
    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;
        for (int j=0; j<k; j++) {
            cin >> tmp;
            M[u-1][tmp-1] = 1;
        }
    }
    dfs();
    return 0;
}

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

vector<int> graph[100];
int d[100], f[100];
int visited = 1;

void dfs(int id){
    d[id] = visited++;
    for(int i = 0; i < graph[id].size(); i++)
	{
        if(graph[id][i] != id && !d[graph[id][i]] && !f[graph[id][i]])
		{
			dfs(graph[id][i]);
		}
    }
    f[id] = visited++;
}

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 v;
            cin >> v;
            graph[u - 1].push_back(v - 1);
        }
    }
    dfs(0);
    for(int i = 0;i < n;i++)
	{
        if(!f[i]) 
		{
			dfs(i);
		}
    }
    for(int i = 0;i < n;i++)
	{
        cout << i + 1 << " " << d[i] << " " << f[i] << endl;
    }
    return 0;
}

C++: // Ref : https://book.mynavi.jp/ec/products/detail/id=35408

#include <iostream>
using namespace std;

static const int N = 100;
int G[N][N] = { {} };
int n, t = 0;
int detected_t[N] = {};
int finished_t[N] = {}; 

void depthFirstSearch(int ix) {
	if (!detected_t[ix - 1]) {
		detected_t[ix - 1] = ++t;
		for (int j = 0; G[ix - 1][j]; j++) {
			depthFirstSearch(G[ix - 1][j]);
		}
		if (!finished_t[ix - 1]) finished_t[ix - 1] = ++t;
	}
}

void myCheck() {
	for (int i = 0; i < n; i++) {
		cout << "index " << i + 1 << " : ";
		for (int j = 0; G[i][j]; j++) {
		if (j) cout << " ";
		cout << G[i][j];
		}
		cout << " time " << detected_t[i] << ", " << finished_t[i] << endl;
	}
}

int main() {
	int ix, deg;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> ix >> deg;
		for (int j = 0; j < deg; j++) cin >> G[ix - 1][j];
	}

	for (int i = 0; i < n; i++) depthFirstSearch(i+1);
	//myCheck();

	for (int i = 0; i < n; i++) cout << i + 1 << " " << detected_t[i] << " " << finished_t[i] << endl;

	return 0;
}

C++: 
 // C
 #ifndef _GLIBCXX_NO_ASSERT
 #include <cassert>
 #endif
 #include <cctype>
 #include <cerrno>
 #include <cfloat>
 #include <ciso646>
 #include <climits>
 #include <clocale>
 #include <cmath>
 #include <csetjmp>
 #include <csignal>
 #include <cstdarg>
 #include <cstddef>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
 #include <ctime> 
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 #include <ccomplex>
 #include <cfenv>
 #include <cinttypes>
 #include <cstdbool>
 #include <cstdint>
 #include <ctgmath>
 #include <cwchar>
 #include <cwctype>
 #endif
 
 // C++
 #include <algorithm>
 #include <bitset>
 #include <complex>
 #include <deque>
 #include <exception>
 #include <fstream>
 #include <functional>
 #include <iomanip>
 #include <ios>
 #include <iosfwd>
 #include <iostream>
 #include <istream>
 #include <iterator>
 #include <limits>
 #include <list>
 #include <locale>
 #include <map>
 #include <memory>
 #include <new>
 #include <numeric>
 #include <ostream>
 #include <queue>
 #include <set>
 #include <sstream>
 #include <stack>
 #include <stdexcept>
 #include <streambuf>
 #include <string>
 #include <typeinfo>
 #include <utility>
 #include <valarray>
 #include <vector> 
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 #include <array>
 #include <atomic>
 #include <chrono>
 #include <condition_variable>
 #include <forward_list>
 #include <future>
 #include <initializer_list>
 #include <mutex>
 #include <random>
 #include <ratio>
 #include <regex>
 #include <system_error>
 #include <thread>
 #include <tuple>
 #include <typeindex>
 #include <type_traits>
 #include <unordered_map>
 #include <unordered_set>
 #endif 
using namespace std;
using Graph = vector< vector<int> >;
bool seen[110];
int d[110];
int f[110];

void dfs(Graph &G,int v,int &time){
    seen[v] = true;
    d[v] = time++;
    for(auto nv : G[v]){
        if(seen[nv]) continue;
        dfs(G,nv,time);
    }
    f[v] = time++;
}

int main(){
    int n; cin >> n;
    Graph G(n);
    for(int i=0;i<n;++i){
        int u,k; cin >> u >> k;
        --u;
        if(k==0) continue;
        for(int j=0;j<k;++j){
            int v;
            cin >> v;
            --v;
            G[u].push_back(v);
        }
    }
    int time = 1;
    for(int v=0;v<n;++v){
        if(seen[v]) continue;
        dfs(G,v,time);
    }
    
   
    for(int v=0;v<n;++v){
        cout << v+1 << ' ' << d[v] << ' ' << f[v] << endl;
    }
    return 0;
}