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.awt.Point;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Scanner;
import java.util.StringTokenizer;

public class C {

    void solve() throws IOException {
        int n = si(), m = si();
        ArrayList<HashSet<Integer>> v = new ArrayList<HashSet<Integer>>();
        for (int i = 0; i < n; i++) {
            int l = si();
            HashSet<Integer> h = new HashSet<Integer>();
            for (int j = 0; j < l; j++) {
                h.add(si());
            }
            v.add(h);
        }
        //System.out.println(v);
        boolean b = true;
        while (b) {
            b = false;
            for (int i = 0; b == false && i < v.size(); i++) {
                for (int j = i + 1; b == false && j < v.size(); j++) {
                    if (!Collections.disjoint(v.get(i), v.get(j))) {
                        // join them
                        v.get(i).addAll(v.get(j));
                        v.remove(v.get(j));
                        b = true;
                    }
                }
            }
        }
        int x = 0, y = 0;
        for (int i = 0; i < v.size(); i++) {
            if ( v.get(i).isEmpty())x++;
            else y++;
        }
        y = Math.max(y-1, 0);
        System.out.println(x+y);
    }

    public static void main(String[] Args) throws IOException {
        new C().solve();
    }

    // DISCUSS TIME LIMIT EXCEEDED!!!! PROPER DATA STRUCTURE!!!
    // Use array if possible or the most efficient data structure
    // graph and node

    // ----------------------- Library ------------------------

    // ----------------------- GRAPH ------------------------

    /**
     * important for speed!!! PrintWriter out=new PrintWriter(new
     * OutputStreamWriter(System.out)); out.print(...); out.close();
     * 
     * @param v
     */
    // leap year is 29

    static int[] dx_ = { 0, 0, 1, -1 };
    static int[] dy_ = { 1, -1, 0, 0 };

    int[] year = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

    void initSystem() throws IOException {
        if (br != null)
            br.close();
        br = new BufferedReader(new InputStreamReader(System.in));
    }

    void initFile() throws IOException {
        if (br != null)
            br.close();
        br = new BufferedReader(new InputStreamReader(new FileInputStream(
                "input.txt")));
    }

    void printWriter() {
        try {
            PrintWriter pr = new PrintWriter("output.txt");
            pr.println("hello world");
            pr.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    void comparator() {
        Point[] v = new Point[10];
        Arrays.sort(v, new Comparator<Point>() {
            @Override
            public int compare(Point a, Point b) {
                if (a.x != b.x)
                    return -(a.x - b.x);
                return a.y - b.y;
            }
        });
    }

    double distance(Point a, Point b) {
        double dx = a.x - b.x, dy = a.y - b.y;
        return Math.sqrt(dx * dx + dy * dy);
    }

    Scanner in = new Scanner(System.in);

    String ss() {
        return in.next();
    }

    String sline() {
        return in.nextLine();
    }

    int si() {
        return in.nextInt();
    }

    long sl() {
        return in.nextLong();
    }

    int[] sai(int n) {
        int[] a = new int[n];
        for (int i = 0; i < a.length; i++) {
            a[i] = in.nextInt();
        }
        return a;
    }

    int[] si(int n) {
        int[] a = new int[n];
        for (int i = 0; i < a.length; i++) {
            a[i] = in.nextInt();
        }
        return a;
    }

    long[] sl(int n) {
        long[] a = new long[n];
        for (int i = 0; i < a.length; i++) {
            a[i] = in.nextLong();
        }
        return a;
    }

    String[] ss(int n) {
        String[] a = new String[n];
        for (int i = 0; i < a.length; i++) {
            a[i] = ss();
        }
        return a;
    }

    int[] sai_(int n) {
        int[] a = new int[n + 1];
        for (int i = 1; i <= n; i++) {
            a[i] = in.nextInt();
        }
        return a;
    }

    BufferedReader br;
    StringTokenizer tokenizer;
    {
        br = new BufferedReader(new InputStreamReader(System.in));
    }

    void tok() throws IOException {
        tokenizer = new StringTokenizer(br.readLine());
    }

    int toki() throws IOException {

        return Integer.parseInt(tokenizer.nextToken());
    }

    int[] rint(int n) throws IOException {
        int[] a = new int[n];
        for (int i = 0; i < a.length; i++)
            a[i] = Integer.parseInt(tokenizer.nextToken());

        return a;
    }

    int[] rint_(int n) throws IOException {
        int[] a = new int[n + 1];
        for (int i = 1; i <= n; i++)
            a[i] = Integer.parseInt(tokenizer.nextToken());

        return a;
    }

    String[] rstrlines(int n) throws IOException {
        String[] a = new String[n];
        for (int i = 0; i < n; i++) {
            a[i] = br.readLine();
        }
        return a;
    }

    long tokl() {
        return Long.parseLong(tokenizer.nextToken());
    }

    double tokd() {
        return Double.parseDouble(tokenizer.nextToken());
    }

    String toks() {
        return tokenizer.nextToken();
    }

    String rline() throws IOException {
        return br.readLine();
    }

    List<Integer> toList(int[] a) {
        List<Integer> v = new ArrayList<Integer>();
        for (int i : a)
            v.add(i);
        return v;
    }

    static void pai(int[] a) {
        System.out.println(Arrays.toString(a));
    }

    static int toi(Object s) {
        return Integer.parseInt(s.toString());
    }

    static int[] dx3 = { 1, -1, 0, 0, 0, 0 };
    static int[] dy3 = { 0, 0, 1, -1, 0, 0 };
    static int[] dz3 = { 0, 0, 0, 0, 1, -1 };

    static int[] dx = { 1, 0, -1, 1, -1, 1, 0, -1 }, dy = { 1, 1, 1, 0, 0, -1,
            -1, -1 };

    static int INF = 2147483647; // =2^31-1 // -8
    static long LINF = 922337203854775807L; // -8
    static short SINF = 32767; // -32768

    // finds GCD of a and b using Euclidian algorithm
    public int GCD(int a, int b) {
        if (b == 0)
            return a;
        return GCD(b, a % b);
    }

    static List<String> toList(String[] a) {
        return Arrays.asList(a);
    }

    static String[] toArray(List<String> a) {
        String[] o = new String[a.size()];
        a.toArray(o);
        return o;
    }

    static int[] pair(int... a) {
        return a;
    }
}
