Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)
const INF = 1<<31

func main() {
	scanner.Scan()
	n, _ := strconv.Atoi(scanner.Text())
	arr := make([][]int, n)
	for i := range arr {
		arr[i] = make([]int, n)
	}
	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			arr[i][j] = INF
		}
	}
	for i := 0; i < n; i++ {
		scanner.Scan()
		buf := strings.Split(scanner.Text(), " ")
		input := make([]int, len(buf))
		for j := range input {
			input[j], _ = strconv.Atoi(buf[j])
		}
		x, k := input[0]-1, input[1]
		for j := 0; j < k; j++ {
			y := input[j+2]-1
			arr[x][y] = 1
		}
	}
	for k := 0; k < n; k++ {
		arr[k][k] = 0
		for i := 0; i < n; i++ {
			if arr[i][k] >= INF {
				continue
			}
			for j := 0; j < n; j++ {
				if arr[k][j] >= INF {
					continue
				}
				arr[i][j] = min(arr[i][j], arr[i][k]+arr[k][j])
			}
		}
	}
	scanner.Scan()
	p, _ := strconv.Atoi(scanner.Text())
	for i := 0; i < p; i++ {
		scanner.Scan()
		buf := strings.Split(scanner.Text(), " ")
		input := make([]int, len(buf))
		for j := range input {
			input[j], _ = strconv.Atoi(buf[j])
		}
		s, d, v := input[0]-1, input[1]-1, input[2]
		if arr[s][d] < v {
			fmt.Println(arr[s][d]+1)
		} else {
			fmt.Println("NA")
		}
	}
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

C++: 
#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <memory>
#include <string>

#include <algorithm>
#include <complex>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#include <bitset>

using namespace std;

#ifdef _MSC_VER
#define __typeof__ decltype
#define strtok_r strtok_s
#endif

#define ITER(c)             __typeof__((c).begin())
#define FOREACH(it, c)      for (ITER(c) it=(c).begin(); it != (c).end(); ++it)
#define RITER(c)            __typeof__((c).rbegin())
#define RFOREACH(it, c)     for (RITER(c) it=(c).rbegin(); it != (c).rend(); ++it)
#define REP(i, n)           REPEAT(i, 0, n)
#define RREP(i, n)          RREPEAT(i, 0, n)
#define REPEAT(i, k, n)     for(int i = (k); i < (k+n); ++i)
#define RREPEAT(i, k, n)    for(int i = (k)+(n)-1; i >= (k); --i)
#define FROMTO(i,f,t)       for(int i = f; i < t; i++)
#define ALL(c)              (c).begin(), (c).end()
#define LLPOW(p1,p2)        ((ll)pow((double)(p1), (int)p2))
#define ESIZEOF(A)          (sizeof(A)/sizeof((A)[0]))
#define CIN_NO_SYNC         do { cin.tie(0); ios_base::sync_with_stdio(false); } while(0)
#define GETSTR(p)           fgets((p), sizeof(p), stdin)
#define CHOMP(p)            do{ char *_q = (p) + strlen(p)-1; if(*_q == '\n' || *_q == '\r') *_q = 0; } while(0)
#define FILL(m,v)           memset(m, v, sizeof(m))
#define mp                  make_pair
#define pb                  push_back
template<class _T> _T MAX(_T p1,_T p2){return (p1>p2)?p1:p2;} 
template<class _T> _T MIN(_T p1,_T p2){return (p1<p2)?p1:p2;} 
template <class _Tv> inline string join(const _Tv &v,string sep=" "){
    ostringstream s;FOREACH(it,v){if(it!=v.begin())s<<sep;s<<*it;};return s.str();
}

typedef long long ll;
typedef unsigned long long ull;
typedef double D;
typedef complex<D> P;
#define X real()
#define Y imag()
#define EPS (1e-9)
#define DEQ(p1,p2) (abs((p1)-(p2)) < EPS)

#ifdef _DEBUG
template<class _Tv> inline void _prfe(const char *_n,const _Tv _c,bool _p=false){
    ITER(_c) _it=_c.begin();
    if(_p){cout<<_n<<" = ["<<endl;for(;_it!=_c.end();++_it)cout<<"    "<<*_it<<endl;cout<<"]"<<endl; }
    else{cout<<_n<<" = [ "<<*_it++;for(;_it!=_c.end();++_it)cout<<", "<<*_it;cout<<" ]"<<endl; }
}
#define pf printf
#define pr(n) do{cout<<#n" = "<<(n)<<endl;}while(0)
#define prfe(n) _prfe(#n, n)
#define prfep(n) _prfe(#n, n, true)
#define dbgchk(n) do{if(n)throw;}while(0)
#else
#define pf(...) /* */
#define pr(...) /* */
#define prfe(...) /* */
#define prfep(...) /* */
#define dbgchk(...) /* */
#endif

class WarshallFloyd {
public:
    static const int inf = 1<<29;
    int m_num;
    vector<vector<int> > m;
    void init(int n){
        m_num = n;
        m.resize(n);
        REP(i,n){
            m[i] = vector<int>(n,inf);
            m[i][i] = 0;
        }
    }
    void add(int u, int v, int e){
        dbgchk(u < 0 || u >= m_num || v < 0 || v >= m_num || u == v);
        m[u][v] = e;
    }
    void solve(){
        int n = m_num;
        REP(k,n) REP(i,n) REP(j,n)
            m[i][j] = MIN(m[i][j], m[i][k] + m[k][j]);
    }
    int get(int u, int v){
        dbgchk(u < 0 || u >= m_num || v < 0 || v >= m_num);
        return m[u][v];
    }
};

int main(){
    WarshallFloyd wf;
    int n, p;
    cin >> n;
    wf.init(n);
    REP(i,n){
        int r, k, t;
        cin >> r >> k;
        REP(j,k){
            cin >> t;
            wf.add(r-1,t-1,1);
        }
    }
    wf.solve();

    cin >> p;
    REP(i,p){
        int s,d,v;
        cin >> s >> d >> v;
        int step = wf.get(s-1,d-1);
        if(step == wf.inf || step >= v){
            cout << "NA" << endl;
        } else {
            cout << step+1 << endl;
        }
    }
    return 0;
}

C++: #include <iostream>
#include <algorithm>

using namespace std;

#define MAX 100
#define INF 100000

int main(){
  int n;
  cin >> n;
  int d[MAX][MAX];
  for(int i = 0 ; i < n ; i++){
    for(int j = 0 ; j < n ; j++){
      d[i][j] = INF;
    }
  }
  for(int i = 0 ; i < n ; i++){
    int r,k,t;
    cin >> r >> k; r--;
    for(int j = 0 ; j < k ; j++){
      cin >> t; t--;
      d[r][t] = 1;
    }
  }
  for(int k = 0 ; k < n ; k++){
    for(int i = 0 ; i < n ; i++){
      for(int j = 0 ; j < n ; j++){
        d[i][j] = min(d[i][j],d[i][k]+d[k][j]);
      }
    }
  }
  int p,s,t,v;
  cin >> p;
  for(int i = 0 ; i < p ; i++){
    cin >> s >> t >> v; s--; t--;
    if(d[s][t]+1 <= v){
      cout << d[s][t]+1 << endl;
    }else{
      cout << "NA" << endl;
    }
  }
  return 0;
}

C++: #include<iostream>
#include<queue>

using namespace std;

int main(){

  int n;
    //making graph
    cin >> n;
    
    int data[n+1][n+1];
    
    for(int i = 0; i <= n; i++){
      for(int j = 0; j <= n; j++){
	data[i][j] = 0;
      }
    }
    
    int from, to, conesum;

    for(int i = 0; i < n; i++){
      cin >> from >> conesum;
      for(int j = 0; j < conesum; j++){
	cin >> to;
	data[from][to] = 1;
      }
    }
    //making graph end

    //judge

    int sumpake;
    cin >> sumpake;

    queue<int> Q;

    int ttl, myposi, min, sumin, sumina, finish = 0;

    for(int i = 0; i < sumpake; i++){
      min = 0;
      cin >> from >> to >> ttl;
      myposi = from;
      for(int j = 0; j < ttl; j++){
	if(j != 0){
	  for(int l = 0; l < sumina; l++){
	    //cout << "sumina " << sumina << endl;
	    if(Q.front() == to){
	      min = j;
	      finish = 1;
	      //cout << "much" << endl;
	      break;
	    }
	    myposi = Q.front();
	    //cout << "pop  " << Q.front()<<endl;
	    Q.pop();
	    for(int k = 1; k <= n; k++){
	      if(data[myposi][k] == 1) {
		Q.push(k);
		sumin++;
	      }
	    }
	    
	  }
	  if(finish == 1) break;
	}else{
	  sumin = 0;
	  for(int k = 1; k <= n; k++){
	    if(data[myposi][k] == 1) {
	      Q.push(k);
	      sumin++;
	    }
	  }
	  
	}
	//	for(int k = 1; k <= n; k++){
	//	    if(data[myposi][k] == 1) {
	//	      Q.push(k);
	//	      sumin++;
	//	    }
	//	}
	  sumina = sumin;
	  sumin = 0;
      }

      
      if(min == 0) cout << "NA";
      else cout << min+1;
      cout << endl;
      finish = 0;
      while(!Q.empty()) Q.pop();
    }



  return 0;
}