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.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Stack;

/**
 * Works good for CF
 * 
 * @author cykeltillsalu
 */
public class Prac {

	// some local config
	static boolean test = false;
	static String testDataFile = "testdata.txt";
	static String feedFile = "feed.txt";
	CompetitionType type = CompetitionType.CF;
	private static String ENDL = "\n";

	// solution
	private void solve() throws Throwable {

		int n = iread();
		iread();

		List[] edges = new List[n];
		int ksum = 0;
		for (int i = 0; i < n; i++) {
			edges[i] = new ArrayList();

			int k = iread();
			ksum
			 += k;
			for (int j = 0; j < k; j++) {
				edges[i].add(iread());
			}
		}
		if(ksum == 0){
			System.out.println(n);
			return;
		}

		Stack<Integer> stack = new Stack<Integer>();
		boolean[] in = new boolean[n];
		in[0] = true;
		stack.add(0);
		int cnt = 0;

		while (true) {

			while (stack.size() > 0) {
				Integer pop = stack.pop();
				for (int i = 0; i < n; i++) {
					if (i == pop || in[i]) {
						continue;
					}
					for (int j = 0; j < edges[pop].size(); j++) {
						Integer a = (Integer) edges[pop].get(j);
						for (int k = 0; k < edges[i].size(); k++) {
							Integer b = (Integer) edges[i].get(k);

							if (a.equals(b)) {
								stack.push(i);
								in[i] = true;
							}
						}
					}
				}
			}

			boolean found = false;

			for (int i = 0; i < n; i++) {
				if (!in[i]) {
					found = true;
					stack.add(i);
					in[i] = true;
					cnt++;
					break;
				}
			}

			if (!found) {
				break;
			}
		}

		System.out.println(cnt);

	}

	public int iread() throws Exception {
		return Integer.parseInt(wread());
	}

	public double dread() throws Exception {
		return Double.parseDouble(wread());
	}

	public long lread() throws Exception {
		return Long.parseLong(wread());
	}

	public String wread() throws IOException {
		StringBuilder b = new StringBuilder();
		int c;
		c = in.read();
		while (c >= 0 && c <= ' ')
			c = in.read();
		if (c < 0)
			return "";
		while (c > ' ') {
			b.append((char) c);
			c = in.read();
		}
		return b.toString();
	}

	public static void main(String[] args) throws Throwable {

		if (test) { // run all cases from testfile:
			BufferedReader testdataReader = new BufferedReader(new FileReader(testDataFile));
			String readLine = testdataReader.readLine();
			int casenr = 0;
			out: while (true) {
				BufferedWriter w = new BufferedWriter(new FileWriter(feedFile));
				if (!readLine.equals("input")) {
					break;
				}
				while (true) {
					readLine = testdataReader.readLine();
					if (readLine.equals("output")) {
						break;
					}
					w.write(readLine + "\n");
				}
				w.close();
				System.out.println("Answer on case " + (++casenr) + ": ");

				new Prac().solve();
				System.out.println("Expected answer: ");

				while (true) {
					readLine = testdataReader.readLine();

					if (readLine == null) {
						break out;
					}
					if (readLine.equals("input")) {
						break;
					}
					System.out.println(readLine);
				}
				System.out.println("----------------");
			}
			testdataReader.close();
		} else { // run on server
			new Prac().solve();
		}
		out.close();
	}

	public Prac() throws Throwable {
		if (test) {
			in = new BufferedReader(new FileReader(new File(feedFile)));
		}
	}

	InputStreamReader inp = new InputStreamReader(System.in);
	BufferedReader in = new BufferedReader(inp);
	static BufferedWriter out = new BufferedWriter(new OutputStreamWriter(System.out));

	enum CompetitionType {
		CF, OTHER
	};
	// BufferedReader in = new BufferedReader(new FileReader("input.txt"));
	// out = new BufferedWriter(new FileWriter("output.txt"));
}