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.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;


import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.PriorityQueue;
import java.util.Random;
import java.util.StringTokenizer;



public final class CF_338_Bulbs {

	void log(int[] X){
		int L=X.length;
		for (int i=0;i<L;i++){
			logWln(X[i]+" ");
		}
		log("");
	}


	void log(long[] X){
		int L=X.length;
		for (int i=0;i<L;i++){
			logWln(X[i]+" ");
		}
		log("");
	}
	void log(Object[] X){
		int L=X.length;
		for (int i=0;i<L;i++){
			logWln(X[i]+" ");
		}
		log("");
	}


	void log(Object o){
		logWln(o+"\n");
	}

	void logWln(Object o){
		System.out.print(o);
		//outputWln(o);

	}
	void info(Object o){
		System.out.println(o);
		//output(o);
	}

	void output(Object o){

		outputWln(""+o+"\n");

	}

	void outputWln(Object o){
		// System.out.print(o);

		try {
			out.write(""+ o);
		} catch (Exception e) {

		}
	}

	void solve(){
		
	}

	BufferedWriter out;
	int N,M;

	
	void process() throws Exception {

		out = new BufferedWriter(new OutputStreamWriter(System.out));
		InputReader reader=new InputReader(System.in);
		N=reader.readInt();
		M=reader.readInt();
		boolean[] ok=new boolean[M];
		int cnt=M;
		for (int i=0;i<N;i++){
			int x=reader.readInt();
			for (int j=0;j<x;j++) {
				int y=reader.readInt()-1;
				if (!ok[y]){
					cnt--;
					ok[y]=true;
				}
			}
		}
		if (cnt==0){
			output("YES");
		} else
			output("NO");
	
		try {
			out.close();
		}
		catch (Exception e){}


	}



	public static void main(String[] args) throws Exception {
		CF_338_Bulbs J=new CF_338_Bulbs();

		J.process();


	}


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

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

		private int read() throws IOException {
			if (curChar >= numChars) {
				curChar = 0;
				numChars = stream.read(buf);
				if (numChars <= 0) {
					return -1;
				}
			}
			return buf[curChar++];
		}


		public final String readString() throws IOException {
			int c = read();
			while (isSpaceChar(c)) {
				c = read();
			}
			StringBuilder res=new StringBuilder();
			do {
				res.append((char)c);
				c = read();
			} while (!isSpaceChar(c));
			return res.toString();
		}

		public final int readInt() throws IOException {
			int c = read();
			boolean neg=false;
			while (isSpaceChar(c)) {
				c = read();
			}
			char d=(char)c;
			//log("d:"+d);
			if (d=='-') {
				neg=true;
				c = read();
			}
			int res = 0;
			do {
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			//log("res:"+res);
			if (neg)
				return -res;
			return res;

		}

		public final long readLong() throws IOException {
			int c = read();
			boolean neg=false;
			while (isSpaceChar(c)) {
				c = read();
			}
			char d=(char)c;
			//log("d:"+d);
			if (d=='-') {
				neg=true;
				c = read();
			}
			long res = 0;
			do {
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			//log("res:"+res);
			if (neg)
				return -res;
			return res;

		}




		private boolean isSpaceChar(int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}
	}

} 