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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
import java.util.Set;
import java.util.Stack;
import java.util.TreeSet;


 
 
public class ck {
 
	static int n;
	static int m;
	
	static ArrayList list[];
	
	public static void main(String[] args) throws NumberFormatException, IOException{
		
		Scanner in = new Scanner(System.in);
		
		n = in.nextInt();
		m = in.nextInt();
		
		list = new ArrayList[m];
		boolean b = false;
		
		int c = 0;
		boolean visited[] = new boolean[m];
		
		for(int i = 0;i<m;i++){
			list[i] = new ArrayList();
		}
		
		HashSet<Integer> set = new HashSet<Integer>();
		for(int i = 0;i<n;i++){
			int l = in.nextInt();
			
			if(l == 0){
				c++;
			}else{
				b = true;
			}
			
			int arr[] = new int[l];
			
			for(int j = 0;j<l;j++){
				arr[j] = in.nextInt();
				set.add(arr[j]-1);
			}
			
			for(int j = 0;j<l;j++){
				for(int k = j+1;k<l;k++){
					list[arr[j]-1].add(arr[k]-1);
					list[arr[k]-1].add(arr[j]-1);
				}
			}
			
			
		}
		
		
		for(int i = 0;i<m;i++){
			if(!set.contains(i)){
				visited[i] = true;
			}
		}
		
		for(int i = 0;i<m;i++){
			
			if(visited[i]){
				continue;
			}
			
			c++;
			Queue<Integer> q=new LinkedList<Integer>();
			q.add(i);
			
			while(!q.isEmpty()){
				int a = q.poll();
				Iterator<Integer> j = list[a].listIterator();
				
				
				while(j.hasNext()){
	    		
					int k = j.next();
					if(visited[k])
	    				continue;
	    			else{
	    				visited[k] = true;
	    				q.add(k);
	    			}
	    		}
				
			}
			
			
		}
		
		if(!b){
			System.out.println(n);
		}else{
			System.out.println(c-1);
		}
		
		
		
}
	
	
	
//	public static void dfs(int i,int j){
//		
//		visited[i][j] = 1;
//		int t1 = i;
//		int t2 = j;
//		
//		for(int p = 0;p<4;p++){
//			
//			i = call[p][0] + t1;
//			j = call[p][1] + t2;
//			
//			if(i >= n || j >=m || i < 0 || j < 0){
//				continue;
//			}
//		//	System.out.println(i+" " + j);
//			if(visited[i][j] == 0){
//				dfs(i,j);
//			}
//			
//		}
//		
//		if(c == 0){
//			return;
//		}else{i = t1;
//		j =t2;
//			if(i >= n || j >=m || i < 0 || j < 0){
//				return;
//			}else{
//				arr[i][j] = 'X';
//				c--;
//			}
//			
//		}
//	
//		
//		
//	}
	
	
	public static boolean isPrime(int n) {
		// Corner cases
		if (n <= 1)
			return false;
		if (n <= 3)
			return true;
 
		// This is checked so that we can skip 
		// middle five numbers in below loop
		if (n % 2 == 0 || n % 3 == 0)
			return false;
 
		for (int i = 5; i * i <= n; i = i + 6)
			if (n % i == 0 || n % (i + 2) == 0)
				return false;
 
		return true;
	}
	
	
	
	public static void Range(int[] numbers, int target) {
	    if (numbers == null)
	        return;

	    int low = 0, high = numbers.length - 1;
	    // get the start index of target number
	    int startIndex = -1;
	    while (low <= high) {
	        int mid = (high - low) / 2 + low;
	        if (numbers[mid] > target) {
	            high = mid - 1;
	        } else if (numbers[mid] == target) {
	            startIndex = mid;
	            high = mid - 1;
	        } else
	            low = mid + 1;
	    }

	    // get the end index of target number
	    int endIndex = -1;
	    low = 0;
	    high = numbers.length - 1;
	    while (low <= high) {
	        int mid = (high - low) / 2 + low;
	        if (numbers[mid] > target) {
	            high = mid - 1;
	        } else if (numbers[mid] == target) {
	            endIndex = mid;
	            low = mid + 1;
	        } else
	            low = mid + 1;
	    }

	    if (startIndex != -1 && endIndex != -1){
	        for(int i=0; i+startIndex<=endIndex;i++){
	            if(i>0)
	                System.out.print(',');
	            System.out.print(i+startIndex);
	        }
	    }
	}
	
	 // union code starts	
	
	 private static void initialize( int Arr[ ],int size[], int N)
	    {
	        for(int i = 0;i<N;i++)
	        {
	        	Arr[ i ] = i ;
	        	size[ i ] = 1;
	        }
	    }
	 
	 private static int root(int Arr[ ],int i)
	    {
	        while(Arr[ i ] != i)           //chase parent of current element until it reaches root
	        {
	            Arr[ i ] = Arr[ Arr[ i ] ] ; 
	            i = Arr[ i ];
	        }
	        return i;
	    }
	 
	 private static void union(int Arr[ ],int size[ ],int A,int B)
	    {
	        int root_A = root(Arr,A);
	        int root_B = root(Arr,B);
	     
	        if(root_A != root_B){
	        	 if(size[root_A] < size[root_B ])
	 	        {
	        		 Arr[ root_A ] = Arr[root_B];
	        		 size[root_B] += size[root_A];	 	
	 	        }
	 	        else
	 	        {   	
	 	        	Arr[ root_B ] = Arr[root_A];
	 	        	size[root_A] += size[root_B];	 	   
	 	        }	
	        }
	    }
	 
	 private static boolean find(int Arr[],int A,int B)
	    {
	        if( root(Arr,A)==root(Arr,B) )       //if A and B have the same root, it means that they are connected.
	        return true;
	        else
	        return false;
	    }
	 
	 
	 // union code ends
	
	
	 
//	 // Segment tree code begins
//	 
//	 
//	 static void build(int node,int start,int end)
//	 {
//	 if(start==end)
//	 tree[node]=a[start];
//	 else
//	 {
//	 int mid=(start+end)/2;
//	 build(2*node,start,mid);
//	 build(2*node+1,mid+1,end);
//	 if(tree[2*node]<tree[2*node+1])
//	 tree[node]=tree[2*node];
//	 else
//	 tree[node]=tree[2*node+1];
//	 }
//	 }
//	 
//	 
//	 static void update(int node,int start,int end,int idx,int val)
//	 {
//	 if(start==end)
//	 {
//	 a[idx]=val;
//	 tree[node]=val;
//	 }
//	 else
//	 {
//	 int mid=(start+end)/2;
//	 if(idx>=start&&idx<=mid)
//	 update(2*node,start,mid,idx,val);
//	 else
//	 update(2*node+1,mid+1,end,idx,val);
//	 if(tree[2*node]<tree[2*node+1])
//	 tree[node]=tree[2*node];
//	 else
//	 tree[node]=tree[2*node+1];
//	 }
//	 }
//	 
//	 static int query(int node,int start,int end,int l,int r)
//	 {
//	 if(l>end||start>r)
//	 return 100005;
//	 if(l<=start&&r>=end)
//	 return tree[node];
//	 int p1,p2;
//	 int mid=(start+end)/2;
//	 p1=query(2*node,start,mid,l,r);
//	 p2=query(2*node+1,mid+1,end,l,r);
//	 if(p1<p2)
//	 return p1;
//	 else
//	 return p2;
//	 }
//	 
//	 
//	 
//}

}

class Node{
	int i;
	int b;
}


class MyComp2 implements Comparator<Node>{
    
	@Override
	public int compare(Node o1, Node o2) {
		if(o1.b>o2.b){
			return 1;
		}else if(o1.b<o2.b){
			return -1;
		}else{
			return 0;
			
			
		}
		
		
	}
}
