The "BerCorp" company has got n employees. These employees can use m approved official languages for the formal correspondence. The languages are numbered with integers from 1 to m. For each employee we have the list of languages, which he knows. This list could be empty, i. e. an employee may know no official languages. But the employees are willing to learn any number of official languages, as long as the company pays their lessons. A study course in one language for one employee costs 1 berdollar.

Find the minimum sum of money the company needs to spend so as any employee could correspond to any other one (their correspondence can be indirect, i. e. other employees can help out translating).

Input

The first line contains two integers n and m (2 ≤ n, m ≤ 100) — the number of employees and the number of languages.

Then n lines follow — each employee's language list. At the beginning of the i-th line is integer ki (0 ≤ ki ≤ m) — the number of languages the i-th employee knows. Next, the i-th line contains ki integers — aij (1 ≤ aij ≤ m) — the identifiers of languages the i-th employee knows. It is guaranteed that all the identifiers in one list are distinct. Note that an employee may know zero languages.

The numbers in the lines are separated by single spaces.

Output

Print a single integer — the minimum amount of money to pay so that in the end every employee could write a letter to every other one (other employees can help out translating).

Examples

Input

5 5
1 2
2 2 3
2 3 4
2 4 5
1 5


Output

0


Input

8 7
0
3 1 2 3
1 1
2 5 4
2 6 7
1 3
2 7 4
1 1


Output

2


Input

2 2
1 2
0


Output

1

Note

In the second sample the employee 1 can learn language 2, and employee 8 can learn language 4.

In the third sample employee 2 must learn language 2.
import java.util.Scanner;
import java.util.Vector;
public class Main277A
{
  public static class UnionFind
  {
    private int[] id;
    private int[] sz;
    private int disjoint;
    public UnionFind(int N)
    {
      id=new int[N];
      sz=new int[N];
      disjoint=N;
      for(int i=0;i<N;i++)
        id[i]=i;
    }
    public int find(int p)
    {
      if(p!=id[p])
      {
        id[p]=find(id[p]);
      }
      return id[p];
    }
    public boolean connected(int p,int q)
    {
      return find(p)==find(q);
    }
    public void union(int p,int q)
    {
      int i=find(p);
      int j=find(q);
      
      if(i==j) return ;
      if(sz[i]>sz[j]){
        id[i]=j;
        sz[j]+=sz[i];
      }
      else
      {
        id[j]=i;
        sz[i]+=sz[j];
      }
      disjoint--;
    }
    public int sets()
    {
      return disjoint;
    }
  }
       
  public static void main(String[] args)
  {
    Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int m=sc.nextInt();
    Vector<Integer>[] a=(Vector<Integer>[]) new Vector[m+1];
    for(int i=0;i<m+1;i++)
      a[i]=new Vector<Integer>();
    for(int i=1;i<=n;i++)
    {
      int val=sc.nextInt();
      for(int j=0;j<val;j++)
      {
        int x=sc.nextInt();
        a[x].add(i);
      }
    }
    UnionFind uf=new UnionFind(n);
    boolean flag=false;
    
    for(int i=1;i<=m;i++)
    {
      if(a[i].size()!=0)
      {
        flag=true;
        int v=a[i].get(0);
        for(int w:a[i])
        {
          //flag=true;
          //System.out.println(v+" "+w);
          uf.union(v-1,w-1);
        }
      }
    }
    if(!flag)
      System.out.println(uf.sets());
    else
      System.out.println(uf.sets()-1);
  }
}
    
    
        
    
    