Problem:
Score : 500 points

Problem Statement

We have N locked treasure boxes, numbered 1 to N.

A shop sells M keys. The i-th key is sold for a_i yen (the currency of Japan), and it can unlock b_i of the boxes: Box c_{i1}, c_{i2}, ..., c_{i{b_i}}. Each key purchased can be used any number of times.

Find the minimum cost required to unlock all the treasure boxes. If it is impossible to unlock all of them, print -1.

Constraints

All values in input are integers.

1 \leq N \leq 12

1 \leq M \leq 10^3

1 \leq a_i \leq 10^5

1 \leq b_i \leq N

1 \leq c_{i1} < c_{i2} < ... < c_{i{b_i}} \leq N

Input

Input is given from Standard Input in the following format:

N M
a_1 b_1
c_{11} c_{12} ... c_{1{b_1}}
:
a_M b_M
c_{M1} c_{M2} ... c_{M{b_M}}

Output

Print the minimum cost required to unlock all the treasure boxes.
If it is impossible to unlock all of them, print -1.

Sample Input 1

2 3
10 1
1
15 1
2
30 2
1 2

Sample Output 1

25

We can unlock all the boxes by purchasing the first and second keys, at the cost of 25 yen, which is the minimum cost required.

Sample Input 2

12 1
100000 1
2

Sample Output 2

-1

We cannot unlock all the boxes.

Sample Input 3

4 6
67786 3
1 3 4
3497 1
2
44908 3
2 3 4
2156 3
2 3 4
26230 1
2
86918 1
3

Sample Output 3

69942

Solution in C# (Mono 4.6.2.0) (judge verdict: Time Limit Exceeded)

using System;
using System.Collections.Generic;//list用
using System.Text;//StringBuilder用
using System.Collections;//ハッシュテーブル用
using System.Linq;

class Program
{
    //Hashtable ht = new Hashtable();
    static List<int> s = new List<int>();
      static List<int> a = new List<int>();
      static List<int> b = new List<int>();
    static List<int>[] c;
  static int val;
    static decimal result;
  static List<int> tmp=new List<int>();
    static int N,K;
    //StringBuilder strresult= new StringBuilder("");//Append(str ○○)関数で文字を追加していく
    static List<decimal> res =new List<decimal>();

    static void Main()
    {
        //Modular mo = new Modular(0);//素数で割った余りを出せで使う。()内が初期値。★使い方：Modular型で宣言すると、その時点でのその素数で割った余りを保持する変数になる（powべき乗、Fac累乗、nCr組み合わせも関数として存在）
        //Node<> no = new Node<>();//UnionFind★Find関数で根っこの値を返す（根っこの値が一緒なら同グループ）、Unite関数で二つの木をくっつける
        //Permutation<> pe = new Permutation<>();//配列＆リストを並べ替えた場合の全ケースを出力★All関数でリスト形式で返す。
        //Treap<> tr = new Treap<>();//平衡二分木★Insert()関数で挿入、FindIndex()関数で該当する大きさの物が入るべき配列番号を返す。
        //PriorityQueue<int,int> pr = new PriorityQueue<int,int>();//優先度付キュー★Add(key,value)で格納、Dequeue()で取りだし。keyが小さいものから取り出す。
Read4();
Read5();

        //各自についてオンの場合とオフの場合をあげる
      result=int.MaxValue-1;
      OnOff(0);
      
      
      
      if(result==int.MaxValue-1){result=-1;}
        Console.WriteLine(result.ToString());

    }
static void OnOff(int num)
{
if(num>=K){
  int[] tmp2=tmp.Distinct().ToArray();
  Array.Sort(tmp2);
  if(tmp2.Length<N){return;}
  for(int i=0;i<N;i++){if(i+1!=tmp2[i]){return;}}
  if(val<result)result=val;
  return;}
OnOff(num+1);
  int lim=c[num].Count;
for(int i=0;i<lim;i++){tmp.Add(c[num][i]);}
  val+=a[num];
OnOff(num+1);
  for(int i=0;i<lim;i++){tmp.Remove(c[num][i]);}
  val-=a[num];
}
  
  
  
    static void Read1()//1項
    {
        string tmp = Console.ReadLine();
        N = int.Parse(tmp);
    }

    static void Read2()//複数項（項目数Ｎ）
    {
        string[] tmp = Console.ReadLine().Split(' ');
        for (int i = 0; i < N; i++) { s.Add(int.Parse(tmp[i])); }
    }
    static void Read3()//1行複数項
    {
        string[] tmp = Console.ReadLine().Split(' ');
        for (int i = 0; i < tmp.Length; i++) { s.Add(int.Parse(tmp[i])); }
    }
    static void Read4()//NK１行
    {
        string[] tmp = Console.ReadLine().Split(' ');
        N = int.Parse(tmp[0]);
        K = int.Parse(tmp[1]);
      c=new List<int>[K];
      for(int i=0;i<K;i++){c[i]=new List<int>();}
    }
    static void Read5()//N行K項
    {
      for(int i=0;i<K;i++)
      {
        string[] tmp = Console.ReadLine().Split(' ');
        a.Add(int.Parse(tmp[0]));
        b.Add(int.Parse(tmp[1]));
        string[] tmp2 = Console.ReadLine().Split(' ');
        for(int j=0;j<b[i];j++){c[i].Add(int.Parse(tmp2[j]));}
      }
    }
}