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.IOException;
import java.io.OutputStreamWriter;
import java.io.BufferedWriter;
import java.util.InputMismatchException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.NoSuchElementException;
import java.io.Writer;
import java.math.BigInteger;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Nguyen Trung Hieu - vuondenthanhcong11@yahoo.com
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        TaskC solver = new TaskC();
        solver.solve(1, in, out);
        out.close();
    }
}

class TaskC {
    public void solve(int testNumber, InputReader in, OutputWriter out) {
        int count = in.readInt();
        int languageCount = in.readInt();
        IntList[] knowLanguage = new IntList[languageCount];
        for (int i = 0; i < languageCount; i++)
            knowLanguage[i] = new IntArrayList();
        boolean atLeastOne = false;
        for (int i = 0; i < count; i++) {
            int currentCount = in.readInt();
            if (currentCount != 0)
                atLeastOne = true;
            for (int j = 0; j < currentCount; j++)
                knowLanguage[in.readInt() - 1].add(i);
        }
        IndependentSetSystem setSystem = new RecursiveIndependentSetSystem(count);
        for (IntList language : knowLanguage) {
            for (int i : language.toArray()) {
                for (int j : language.toArray())
                    setSystem.join(i, j);
            }
        }
        out.printLine(setSystem.getSetCount() - 1 + (!atLeastOne ? 1 : 0));
    }
}

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

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

    }

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();
    }

}

abstract class IntList extends IntCollection {
    private static final int INSERTION_THRESHOLD = 8;

    public abstract int get(int index);
    public abstract void set(int index, int value);

    public IntIterator iterator() {
        return new IntIterator() {
            private int size = size();
            private int index = 0;

            public int value() throws NoSuchElementException {
                if (!isValid())
                    throw new NoSuchElementException();
                return get(index);
            }

            public void advance() throws NoSuchElementException {
                if (!isValid())
                    throw new NoSuchElementException();
                index++;
            }

            public boolean isValid() {
                return index < size;
            }
        };
    }

    private void swap(int first, int second) {
        if (first == second)
            return;
        int temp = get(first);
        set(first, get(second));
        set(second, temp);
    }

    public IntSortedList inPlaceSort(IntComparator comparator) {
        quickSort(0, size() - 1, size(), comparator);
        return new IntSortedArray(this, comparator);
    }

    private void quickSort(int from, int to, int remaining, IntComparator comparator) {
        if (to - from < INSERTION_THRESHOLD) {
            insertionSort(from, to, comparator);
            return;
        }
        if (remaining == 0) {
            heapSort(from, to, comparator);
            return;
        }
        remaining >>= 1;
        int pivotIndex = (from + to) >> 1;
        int pivot = get(pivotIndex);
        swap(pivotIndex, to);
        int storeIndex = from;
        int equalIndex = to;
        for (int i = from; i < equalIndex; i++) {
            int value = comparator.compare(get(i), pivot);
            if (value < 0)
                swap(storeIndex++, i);
            else if (value == 0)
                swap(--equalIndex, i--);
        }
        quickSort(from, storeIndex - 1, remaining, comparator);
        for (int i = equalIndex; i <= to; i++)
            swap(storeIndex++, i);
        quickSort(storeIndex, to, remaining, comparator);
    }

    private void heapSort(int from, int to, IntComparator comparator) {
        for (int i = (to + from - 1) >> 1; i >= from; i--)
            siftDown(i, to, comparator);
        for (int i = to; i > from; i--) {
            swap(from, i);
            siftDown(from, i - 1, comparator);
        }
    }

    private void siftDown(int start, int end, IntComparator comparator) {
        int value = get(start);
        while (true) {
            int child = (start << 1) + 1;
            if (child > end)
                return;
            int childValue = get(child);
            if (child + 1 <= end) {
                int otherValue = get(child + 1);
                if (comparator.compare(otherValue, childValue) > 0) {
                    child++;
                    childValue = otherValue;
                }
            }
            if (comparator.compare(value, childValue) >= 0)
                return;
            swap(start, child);
            start = child;
        }
    }

    private void insertionSort(int from, int to, IntComparator comparator) {
        for (int i = from + 1; i <= to; i++) {
            int value = get(i);
            for (int j = i - 1; j >= from; j--) {
                if (comparator.compare(get(j), value) <= 0)
                    break;
                swap(j, j + 1);
            }
        }
    }

    public IntSortedList sort(IntComparator comparator) {
        return new IntArray(this).inPlaceSort(comparator);
    }

    }

class IntArrayList extends IntList {
    private int[] array;
    private int size;

    public IntArrayList() {
        this(10);
    }

    public IntArrayList(int capacity) {
        array = new int[capacity];
    }

    public int get(int index) {
        if (index >= size)
            throw new IndexOutOfBoundsException();
        return array[index];
    }

    public void set(int index, int value) {
        if (index >= size)
            throw new IndexOutOfBoundsException();
        array[index] = value;
    }

    public int size() {
        return size;
    }

    public void add(int value) {
        ensureCapacity(size + 1);
        array[size++] = value;
    }

    private void ensureCapacity(int newCapacity) {
        if (newCapacity > array.length) {
            int[] newArray = new int[Math.max(newCapacity, array.length << 1)];
            System.arraycopy(array, 0, newArray, 0, size);
            array = newArray;
        }
    }

    public int[] toArray() {
        int[] array = new int[size];
        System.arraycopy(this.array, 0, array, 0, size);
        return array;
    }
}

abstract class IntCollection {
    public abstract IntIterator iterator();
    public abstract int size();
    public abstract void add(int value);

    public int[] toArray() {
        int size = size();
        int[] array = new int[size];
        int i = 0;
        for (IntIterator iterator = iterator(); iterator.isValid(); iterator.advance())
            array[i++] = iterator.value();
        return array;
    }
}

interface IndependentSetSystem {
    public boolean join(int first, int second);

    public int getSetCount();

    public static interface Listener {
        public void joined(int joinedRoot, int root);
    }
}

class RecursiveIndependentSetSystem implements IndependentSetSystem {
    private final int[] color;
    private int setCount;
    private Listener listener;

    public RecursiveIndependentSetSystem(int size) {
        color = new int[size];
        for (int i = 0; i < size; i++)
            color[i] = i;
        setCount = size;
    }

    public RecursiveIndependentSetSystem(RecursiveIndependentSetSystem other) {
        color = other.color.clone();
        setCount = other.setCount;
    }

    public boolean join(int first, int second) {
        first = get(first);
        second = get(second);
        if (first == second)
            return false;
        setCount--;
        color[second] = first;
        if (listener != null)
            listener.joined(second, first);
        return true;
    }

    public int get(int index) {
        if (color[index] == index)
            return index;
        return color[index] = get(color[index]);
    }

    public int getSetCount() {
        return setCount;
    }
}

interface IntIterator {
    public int value() throws NoSuchElementException;
    /*
     * @throws NoSuchElementException only if iterator already invalid
     */
    public void advance() throws NoSuchElementException;
    public boolean isValid();
}

abstract class IntSortedList extends IntList {
    protected final IntComparator comparator;

    protected IntSortedList(IntComparator comparator) {
        this.comparator = comparator;
    }

    public void set(int index, int value) {
        throw new UnsupportedOperationException();
    }

    public void add(int value) {
        throw new UnsupportedOperationException();
    }

    public IntSortedList inPlaceSort(IntComparator comparator) {
        if (comparator == this.comparator)
            return this;
        throw new UnsupportedOperationException();
    }

    public IntSortedList sort(IntComparator comparator) {
        if (comparator == this.comparator)
            return this;
        return super.sort(comparator);
    }

    protected void ensureSorted() {
        int size = size();
        if (size == 0)
            return;
        int last = get(0);
        for (int i = 1; i < size; i++) {
            int current = get(i);
            if (comparator.compare(last, current) > 0)
                throw new IllegalArgumentException();
            last = current;
        }
    }

    }

interface IntComparator {
    public static final IntComparator DEFAULT = new IntComparator() {
        public int compare(int first, int second) {
            if (first < second)
                return -1;
            if (first > second)
                return 1;
            return 0;
        }
    };

    public int compare(int first, int second);
}

class IntSortedArray extends IntSortedList {
    private final int[] array;

    public IntSortedArray(int[] array) {
        this(array, IntComparator.DEFAULT);
    }

    public IntSortedArray(IntCollection collection) {
        this(collection, IntComparator.DEFAULT);
    }

    public IntSortedArray(int[] array, IntComparator comparator) {
        super(comparator);
        this.array = array;
        ensureSorted();
    }

    public IntSortedArray(IntCollection collection, IntComparator comparator) {
        super(comparator);
        array = new int[collection.size()];
        int i = 0;
        for (IntIterator iterator = collection.iterator(); iterator.isValid(); iterator.advance())
            array[i++] = iterator.value();
        ensureSorted();
    }

    public int get(int index) {
        return array[index];
    }

    public int size() {
        return array.length;
    }
}

class IntArray extends IntList {
    private final int[] array;

    public IntArray(int[] array) {
        this.array = array;
    }

    public IntArray(IntCollection collection) {
        array = new int[collection.size()];
        int i = 0;
        for (IntIterator iterator = collection.iterator(); iterator.isValid(); iterator.advance())
            array[i++] = iterator.value();
    }

    public int get(int index) {
        return array[index];
    }

    public void set(int index, int value) {
        array[index] = value;
    }

    public int size() {
        return array.length;
    }

    public void add(int value) {
        throw new UnsupportedOperationException();
    }

    public int[] toArray() {
        return array;
    }
}
