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 <bits/stdc++.h>
#define trace1(a)                    cout<<#a<<": "<<a<<endl
#define trace2(a,b)                  cout<<#a<<": "<<a<<" | ", trace1(b)
#define trace3(a,b,c)                cout<<#a<<": "<<a<<" | ", trace2(b,c)
#define trace4(a,b,c,d)              cout<<#a<<": "<<a<<" | ", trace3(b,c,d)
#define trace5(a,b,c,d,e)            cout<<#a<<": "<<a<<" | ", trace4(b,c,d,e)
#define trace6(a,b,c,d,e,f)          cout<<#a<<": "<<a<<" | ", trace5(b,c,d,e,f)
#define trace7(a,b,c,d,e,f,g)        cout<<#a<<": "<<a<<" | ", trace6(b,c,d,e,f,g)
#define trace8(a,b,c,d,e,f,g,h)      cout<<#a<<": "<<a<<" | ", trace7(b,c,d,e,f,g,h)
#define trace9(a,b,c,d,e,f,g,h,i)    cout<<#a<<": "<<a<<" | ", trace8(b,c,d,e,f,g,h,i)
#define trace10(a,b,c,d,e,f,g,h,i,j) cout<<#a<<": "<<a<<" | ", trace9(b,c,d,e,f,g,h,i,j)
#define rep(i,a,b)      for(int (i)=(int)(a);(i)<(int)(b); ++(i))
#define reps(i,a,b,c)   for(int (i)=(int)(a);(i)<(int)(b); (i)+=(c))
#define rrep(i,a,b)     for(int (i)=(int)(a);(i)>=(int)(b);--(i))
#define rreps(i,a,b,c)  for(int (i)=(int)(a);(i)>=(int)(b);(i)-=(c))
#define fore(x,a)       for(auto &x:a)
#define foreach(i,a)    for(auto i=(a).begin(); i!=(a).end(); ++i)
#define rforeach(i,a)   for(auto i=(a).rbegin();i!=(a).rend();++i)
#define all(a)  (a).begin(), (a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define isin(i,a,b) ((a) <= (i) && (i) <= (b))
#define uni(a) (a).erase(unique(all(a)),(a).end())
#define dup(x,y) (((x)+(y)-1)/(y))
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define sz(a) ((long long)(a).size())
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
using ll  = long long;          using vi  = vector<int>;
using unit= unsigned;           using vl  = vector<ll>;
using ull = unsigned long long; using vvi = vector<vi>;
                                using vvl = vector<vl>;
using pii = pair<int,int>;      using vpii= vector<pii>;
using pil = pair<int,ll>;       using vpil= vector<pil>;
using pli = pair<ll,int>;       using vpli= vector<pli>;
using pll = pair<ll,ll>;        using vpll= vector<pll>;
void _main(); int main(){ cin.tie(0); ios::sync_with_stdio(false); _main(); }
template<class T>string join(const v(T)&v){ stringstream s; rep(i,0,sz(v))s<<' '<<v[i]; return s.str().substr(1); }
template<class T>istream &operator>>(istream&i, v(T)&v){ fore(x,v){ i >> v; } return i; }
template<class T>ostream &operator<<(ostream&o, const v(T)&v){ o<<"["; fore(x,v)o<<x<<","; o<<"]"; return o; }
template<class T>ostream &operator<<(ostream&o, const deque<T>&v){ o<<"deq["; fore(x,v)o<<x<<","; o<<"]"; return o; }
template<class T>ostream &operator<<(ostream&o, const set<T>&v){ o<<"{"; fore(x,v)o<<x<<","; o<<"}"; return o; }
template<class T>ostream &operator<<(ostream&o, const unordered_set<T>&v){ o<<"{"; fore(x,v)o<<x<<","; o<<"}"; return o; }
template<class T>ostream &operator<<(ostream&o, const multiset<T>&v){ o<<"{"; fore(x,v)o<<x<<","; o<<"}"; return o; }
template<class T>ostream &operator<<(ostream&o, const unordered_multiset<T>&v){ o<<"{"; fore(x,v)o<<x<<","; o<<"}"; return o; }
template<class T1,class T2>ostream &operator<<(ostream &o, const pair<T1,T2>&p){ o<<"("<<p.fi<<","<<p.se<<")"; return o; }
template<class TK,class TV>ostream &operator<<(ostream &o, const map<TK,TV>&m){ o<<"{"; fore(x,m)o<<x.fi<<"=>"<<x.se<<","; o<<"}"; return o; }
template<class TK,class TV>ostream &operator<<(ostream &o, const unordered_map<TK,TV>&m){ o<<"{"; fore(x,m)o<<x.fi<<"=>"<<x.se<<","; o<<"}"; return o; }
template<class T>void YES(T c){ if(c) cout<<"YES"<<endl; else cout<<"NO"<<endl; }
template<class T>void Yes(T c){ if(c) cout<<"Yes"<< endl; else cout<<"No"<<endl; }
template<class T>void POSS(T c){ if(c) cout<<"POSSIBLE"<<endl; else cout<<"IMPOSSIBLE"<<endl; }
template<class T>void Poss(T c){ if(c) cout<<"Possible"<<endl; else cout<<"Impossible"<<endl; }
template<class T>void chmax(T &a, const T &b){ if(a<b) a=b; }
template<class T>void chmin(T &a, const T &b){ if(b<a) a=b; }
template<class T>T gcd(T a, T b){ return b?gcd(b,a%b):a; }
template<class T>T lcm(T a, T b){ return a/gcd(a,b)*b; }
const double  EPS = 1e-10;
const double  PI  = acos(-1.0);
const int     INF = 1001002003;
const ll      LINF= 1001002003004005006LL;
const int dx[] = { -1, 0, 1, 0 , -1,-1, 1, 1 };
const int dy[] = {  0, 1, 0,-1 , -1, 1,-1, 1 };

int n;
vvi G;
int cnt = 1;
vvi ans;

void dfs(int i=-1) {
  if (ans[i][1] != 0) return;
  ans[i][1] = cnt++;
  fore(x,G[i]) dfs(x);
  ans[i][2] = cnt++;
}

void _main() {
  cin >> n;
  G.resize(n);
  ans.resize(n, vi(3));
  rep(i,0,n) ans[i][0] = i+1;
  rep(i,0,n) {
    int a, m;
    cin >> a >> m;
    --a;
    rep(j,0,m) {
      int b;
      cin >> b;
      --b;
      G[a].pb(b);
    }
  }
  rep(i,0,n) if (ans[i][1] == 0) dfs(i);
  fore(x,ans) {
    cout << x[0] << " " << x[1] << " " << x[2] << endl;
  }
}

C++: #include <stdio.h>
#define N 100
#define WHITE 0;
#define GRAY 1;
#define BRACK 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] = BRACK;
  f[u] = ++tt;
  
}

void dfs() {
  int u;
  for ( u = 0; u < n; u++ ) color[u] = WHITE;
  tt = 0;
  
  for ( u = 0; u < n; 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, i, j;
  
  scanf("%d", &n);
  for ( i = 0; i < n; i++ ){
    for ( j = 0; j < n; j++ ) M[i][j] = 0;
  }
  
  for ( i = 0; i < n; i++ ) {
    scanf("%d %d", &u, &k );
    u--;
    for ( j = 0; j < k; j++ ) {
      scanf("%d", &v);
      v--;
      M[u][v] = 1;
    }
  }
    
    dfs();
    
    return 0;
}