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.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.Scanner;
import java.util.TreeMap;

public class Solution{
	
	///////////////////////////////////////////////////////////////////////////
	static class FastScanner{
		BufferedReader s;
		StringTokenizer st;
		
		public FastScanner(){
			st = new StringTokenizer("");
			s = new BufferedReader(new InputStreamReader(System.in));
		}
		
		public FastScanner(File f) throws FileNotFoundException{
			st = new StringTokenizer("");
			s = new BufferedReader (new FileReader(f));
		}
		
		public int nextInt() throws IOException{
			if(st.hasMoreTokens())
				return Integer.parseInt(st.nextToken());
			else{
				st = new StringTokenizer(s.readLine());
				return nextInt();
			}
		}
		
		public double nextDouble() throws IOException{
			if(st.hasMoreTokens())
				return Double.parseDouble(st.nextToken());
			else{
				st = new StringTokenizer(s.readLine());
				return nextDouble();
			}
		}
		
		public long nextLong() throws IOException{
			if(st.hasMoreTokens())
				return Long.parseLong(st.nextToken());
			else{
				st = new StringTokenizer(s.readLine());
				return nextLong();
			}
		}
		
		public String nextString() throws IOException{
			if(st.hasMoreTokens())
				return st.nextToken();
			else{
				st = new StringTokenizer(s.readLine());
				return nextString();
			}
			
		}
		public String readLine() throws IOException{
			return s.readLine();
		}
		
		public void close() throws IOException{
			s.close();
		}
		
	}
	
	////////////////////////////////////////////////////////////////////
	//		Number Theory
	
	public static int divisor(int x){
	    int limit = x;
	    int numberOfDivisors = 0;

	    for (int i=1; i < limit; ++i) {
	        if (x % i == 0) {
	            limit = x / i;
	            if (limit != i) {
	                numberOfDivisors++;
	            }
	            numberOfDivisors++;
	        }
	    }

	    return numberOfDivisors;
    }
	
	
	public static long gcd(long a, long b){
		return b == 0 ? a : gcd(b,a%b);
	}
	
  
	public static long lcm(long a,long b, long c){
		return lcm(lcm(a,b),c);
	}
	
	public static long lcm(long a, long b){
		return a*b/gcd(a,b);
	}
	
	
	////////////////////////////////////////////////////////////////////
	
	
//	  private static  	FastScanner s = new FastScanner(new File("input.txt"));
//	  private static PrintWriter ww = new PrintWriter(new FileWriter("output.txt"));
	  private static FastScanner s = new FastScanner();   
      private static PrintWriter ww = new PrintWriter(new OutputStreamWriter(System.out));
//    private static Scanner s = new Scanner(System.in);
      @SuppressWarnings("unused")
	private static Map<Integer,Integer> mm = new HashMap<Integer,Integer>();
      @SuppressWarnings("unused")
	private static Map<Integer,node> mn = new HashMap<Integer,node>();
	@SuppressWarnings("rawtypes")
	private static ArrayList[] arr = new ArrayList[103];
	private static boolean[] vis = new boolean[103];
	private static boolean[] check = new boolean[103];
	private static int ans = 0;
      
    //////////////////////////////////////////////////////////////////// 
      
     static class node{
      	int l;
      	int r;
      	int d;
      	public node(int x, int y, int z){
      		this.l  = x;
      		this.r = y;
      		this.d = z;
      	}
      }
    
    public static void dfs(int n){
    	vis[n] = true;
    	for(int i=0;i<arr[n].size();i++){
    		if(vis[(int)arr[n].get(i)] == false){
    			dfs((int)arr[n].get(i));
    		}
    	}
    }
     
      
	public static void main(String[] args) throws IOException{
	
	    int n = s.nextInt();
	    int m = s.nextInt();
	    int va = 0;
	    
	    for(int i=0;i<103;i++) arr[i] = new ArrayList<Integer>();
	    
	    for(int i=0;i<n;i++){
	    	int x = s.nextInt();
	    	if(x == 0){ 
	    		ans++; va++;
	    	}
	    	else if(x == 1){
	    		int one = s.nextInt();
	    		check[one] = true;
	    	}else{
	    		int one = s.nextInt();
	    		check[one] = true;
	    		for(int ii=0;ii<x-1;ii++){
	    			int xx = s.nextInt();
	    			check[xx] = true;
	    			arr[one].add(xx);
	    			arr[xx].add(one);
	    		}
	    	}
	    	
	    }
	    
	    for(int i=0;i<=m;i++){
	    	if(check[i] == true && vis[i] == false){
	    		ans++;
	    		dfs(i);
	    	}
	    }
	    
	    if(va == n) ww.println(n);
	    else	ww.println(ans-1);
	    s.close();
	    ww.close();
	}
}
