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.*;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.*;
import java.math.*;




public class Solution
{
	
	static StringBuilder sb;
	static dsu dsu;
	static long fact[];
	static long mod=(long)(1e9+7);
	static ArrayList<Integer>prime;
	static int A[];
	static boolean visited[];
	static ArrayList<Integer>adj[];
	static void solve()
    {
		int n=i(),m=i();
		
		adj=new ArrayList[m+1];
		
		for(int i=1;i<=m;i++)
	   adj[i]=new ArrayList<>();
		int allzero=0;
		
		
		for(int i=1;i<=n;i++)
		{
			int u=i;
			int k=i();
			if(k==0)
				allzero++;
			
			for(int j=0;j<k;j++)
			{
				int v=i();
				adj[v].add(u);
			}
		}
		dsu dsu=new dsu(n);
		
		for(int i=1;i<=m;i++)
		{
			for(int j=0;j<adj[i].size()-1;j++)
			{
				int u=adj[i].get(j);
				int v=adj[i].get(j+1);
				
				dsu.merge(u,v);
			}
		}
		int cnt=0;
		for(int i=1;i<=n;i++)
		{
			if(dsu.parent[i]<0)
				cnt++;
		}
		
		if(allzero==n)
			cnt=n+1;
		
		System.out.println(cnt-1);
		
		
		
		
		
		
    }
	public static void main(String[] args)
	 {
		 sb=new StringBuilder();
	    
		 
	     int test=1;
	    
	     
	     for(int tt=1;tt<=test;tt++) 
	    {
	         solve();
	    }
	     System.out.println(sb);
	 }
	 
//*******************************************NCR%P*******************************************************	 
	 static long ncr(int n, int r)
	 {
		 if(r>n)
			 return (long)0;
		 
		 long res=fact[n]%mod;
		 //System.out.println(res);
		 res=((long)(res%mod)*(long)(p(fact[r],mod-2)%mod))%mod;
		 res=((long)(res%mod)*(long)(p(fact[n-r],mod-2)%mod))%mod;
		 //System.out.println(res);
		 return res;
		
		 
	 }
		static long p(long x, long y)//POWER FXN //
		{
			if(y==0)
				return 1;
			
			long res=1;
			while(y>0)
			{
				if(y%2==1)
				{
					res=(res*x)%mod;
					y--;
				}
				
				x=(x*x)%mod;
				y=y/2;
				
				
			}
			return res;
		}
		static long ceil(long num, long den)
		{
			return (long)(num+den-1)/den;
		}
		

//*******************************************END*******************************************************
		static int LowerBound(long a[], long x, int i, int j) 
		{ 
			//X is the key value
			int l=i;int r=j;
			int lb=-1;
			  while(l<=r)
			  {
			    int m=(l+r)/2;
			    
			    if(a[m]>=x) 
			    {
			    	lb=m;
			    	r=m-1;
			    }
			    else l=m+1;
			  }
			  return lb;
		}
		static int UpperBound(long a[], long x, int i, int j) 
		{// x is the key or target value
		    int l=i,r=j;
		    int ans=-1;
		    while(l<=r)
		    {
		       int m=(l+r)/2;
		       
		       if(a[m]<=x) 
		       {
		    	   ans=m;
		    	   l=m+1;
		       }
		       else r=m-1;
		    }
		    return ans;
		 }
		
		
		
	 
	 
	 //*********************************Disjoint set union*************************//
	 static class dsu
	 {
		 int parent[];
		 dsu(int n)
		 {
			 parent=new int[n+1];
			 for(int i=0;i<=n;i++)
				 parent[i]=-1;
		 }
		 int find(int a)
		 {
			 if(parent[a]<0)
				 return a;
			 else
			 {
				 int x=find(parent[a]);
				 parent[a]=x;
				 return x;
			 }
		 }
		 void merge(int a,int b)
		 {
			 a=find(a);
			 b=find(b);
			 if(a==b)
				 return;
			 parent[b]=a;
		 }
	 }
	 
	 
	 
//*******************************************PRIME FACTORIZE *****************************************************************************************************//
	 static TreeMap<Integer,Integer> prime(long n)
	 {
		 TreeMap<Integer,Integer>h=new TreeMap<>();
		 long num=n;
		 for(int i=2;i<=Math.sqrt(num);i++)
		 {
			 if(n%i==0)
			 {
				 int nt=0;
				 while(n%i==0) {
					 n=n/i;
					 nt++;
				 }
				 h.put(i, nt);
			 }
		 }
		 if(n!=1)
			 h.put((int)n, 1);
		 return h;
		 
	 }
	 
	
	
//*************CLASS PAIR ***********************************************************************************************************************************************
	    static class pair implements Comparable<pair>
	    {
	        int x;
	        int  y;
	        
	        pair(int x, int y) {
	            this.x = x;
	            this.y = y;
	           
	        }
	        public int compareTo(pair o)
	        {
	        	return(int) (y-o.y);
	        	
	        }
			
	       
	    }
//*************CLASS PAIR *****************************************************************************************************************************************************
	
	
	

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1)
                throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int Int() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public String String() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return String();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
        }
    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0)
                    writer.print(' ');
                writer.print(objects[i]);
            }
        }

        public void printLine(Object... objects) {
            print(objects);
            writer.println();
        }

        public void close() {
            writer.close();
        }

        public void flush() {
            writer.flush();
        }
    }

    static InputReader in = new InputReader(System.in);
    static OutputWriter out = new OutputWriter(System.out);
   

    public static int[] sort(int[] a) {
        int n = a.length;
        ArrayList<Integer> l = new ArrayList<>();
        for (int i : a)
            l.add(i);
        Collections.sort(l);
        for (int i = 0; i < l.size(); i++)
            a[i] = l.get(i);
        return a;
    }
    public static long[] sort(long[] a) {
        int n = a.length;
        ArrayList<Long> l = new ArrayList<>();
        for (long i : a)
            l.add(i);
        Collections.sort(l);
        for (int i = 0; i < l.size(); i++)
            a[i] = l.get(i);
        return a;
    }

    public static long pow(long x, long y) {
        long res = 1;
        while (y > 0) {
            if (y % 2 != 0) {
                res = (res * x);// % modulus;
                y--;

            }
            x = (x * x);// % modulus;
            y = y / 2;
        }
        return res;
    }
//GCD___+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    public static long gcd(long x, long y) {
        if (x == 0)
            return y;
        else
            return gcd(y % x, x);
    }
    //****************LOWEST COMMON MULTIPLE   *************************************************************************************************************************************

    public static long lcm(long x, long y) {
        return (x * (y / gcd(x, y)));
    }
//INPUT PATTERN******************************************************************************************************************************************************************
    public static int i() {
        return in.Int();
    }

    public static long l() {
        String s = in.String();
        return Long.parseLong(s);
    }

    public static String s() {
        return in.String();
    }

    public static int[] readArray(int n) {
        int A[] = new int[n];
        for (int i = 0; i < n; i++) {
            A[i] = i();
        }
        return A;
    }

    public static long[] readArray(long n) {
        long A[] = new long[(int) n];
        for (int i = 0; i < n; i++) {
            A[i] = l();
        }
        return A;
    }
    public int[][] deepCopy(int[][] matrix) {
		return java.util.Arrays.stream(matrix).map(el -> el.clone()).toArray($ -> matrix.clone());
		}
 

}






	