Vasya wants to turn on Christmas lights consisting of m bulbs. Initially, all bulbs are turned off. There are n buttons, each of them is connected to some set of bulbs. Vasya can press any of these buttons. When the button is pressed, it turns on all the bulbs it's connected to. Can Vasya light up all the bulbs?

If Vasya presses the button such that some bulbs connected to it are already turned on, they do not change their state, i.e. remain turned on.

Input

The first line of the input contains integers n and m (1 ≤ n, m ≤ 100) — the number of buttons and the number of bulbs respectively. 

Each of the next n lines contains xi (0 ≤ xi ≤ m) — the number of bulbs that are turned on by the i-th button, and then xi numbers yij (1 ≤ yij ≤ m) — the numbers of these bulbs.

Output

If it's possible to turn on all m bulbs print "YES", otherwise print "NO".

Examples

Input

3 4
2 1 4
3 1 3 1
1 2


Output

YES


Input

3 3
1 1
1 2
1 1


Output

NO

Note

In the first sample you can press each button once and turn on all the bulbs. In the 2 sample it is impossible to turn on the 3-rd lamp.

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class P615A {
  InputStream is;
  PrintWriter out;
  String INPUT0 = "3 4 2 1 4 3 1 3 1 1 2";
  String INPUT = "3 3 1 1 1 2 1 1";
  
  void solve() {
    int n = ni();
    int m = ni();
    boolean[] lights = new boolean[m];
    for (int i = 0; i < n; i++) {
      int k = ni();
      for (int j = 0; j < k; j++) {
        lights[ni() - 1] = true;
      }
    }

    for (int i = 0; i < m; i++) {
      if (!lights[i]) {
        System.out.println("NO");
        return;
      }
    }
    System.out.println("YES");
  }
  
  public static void main(String[] args) throws Exception {
    new P615A().run();
  }
  
  void run() throws Exception {
    is = oj ? System.in : new ByteArrayInputStream(INPUT.getBytes());
    out = new PrintWriter(System.out);
  
    long s = System.currentTimeMillis();
    solve();
    out.flush();
    tr(System.currentTimeMillis() - s + "ms");
  }
  
  private byte[] inbuf = new byte[1024];
  private int lenbuf = 0, ptrbuf = 0;
  
  private int readByte() {
    if (lenbuf == -1)
      throw new InputMismatchException();
    if (ptrbuf >= lenbuf) {
      ptrbuf = 0;
      try {
        lenbuf = is.read(inbuf);
      } catch (IOException e) {
        throw new InputMismatchException();
      }
      if (lenbuf <= 0)
        return -1;
    }
    return inbuf[ptrbuf++];
  }
  
  private boolean isSpaceChar(int c) {
    return !(c >= 33 && c <= 126);
  }
  
  private int skip() {
    int b;
    while ((b = readByte()) != -1 && isSpaceChar(b))
      ;
    return b;
  }
  
  private double nd() {
    return Double.parseDouble(ns());
  }
  
  private char nc() {
    return (char) skip();
  }
  
  private String ns() {
    int b = skip();
    StringBuilder sb = new StringBuilder();
    while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != ' ')
      sb.appendCodePoint(b);
      b = readByte();
    }
    return sb.toString();
  }
  
  private char[] ns(int n) {
    char[] buf = new char[n];
    int b = skip(), p = 0;
    while (p < n && !(isSpaceChar(b))) {
      buf[p++] = (char) b;
      b = readByte();
    }
    return n == p ? buf : Arrays.copyOf(buf, p);
  }
  
  private char[][] nm(int n, int m) {
    char[][] map = new char[n][];
    for (int i = 0; i < n; i++)
      map[i] = ns(m);
    return map;
  }
  
  private int[] na(int n) {
    int[] a = new int[n];
    for (int i = 0; i < n; i++)
      a[i] = ni();
    return a;
  }
  
  private int ni() {
    int num = 0, b;
    boolean minus = false;
    while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
      ;
    if (b == '-') {
      minus = true;
      b = readByte();
    }
  
    while (true) {
      if (b >= '0' && b <= '9') {
        num = num * 10 + (b - '0');
      } else {
        return minus ? -num : num;
      }
      b = readByte();
    }
  }
  
  private long nl() {
    long num = 0;
    int b;
    boolean minus = false;
    while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
      ;
    if (b == '-') {
      minus = true;
      b = readByte();
    }
  
    while (true) {
      if (b >= '0' && b <= '9') {
        num = num * 10 + (b - '0');
      } else {
        return minus ? -num : num;
      }
      b = readByte();
    }
  }
  
  private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
  
  private void tr(Object... o) {
    if (!oj)
      System.out.println(Arrays.deepToString(o));
  }
}
