import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.Comparator;
import java.util.NoSuchElementException;
import java.util.Scanner;

public class Main {	
	public static void main(String[] args) {
		//long t = System.currentTimeMillis();
		new Main().run();
		//System.err.println(System.currentTimeMillis() - t);
	}
	
	int flip(int pos,int W) {
		return W-1-pos;
	}
	
	void run() {
		Scanner sc=new Scanner(System.in);
		int N=sc.nextInt();
		int M=sc.nextInt();
		int[][] A=new int[N][2];
		for(int i=0;i<N;++i) {
			A[i][0]=sc.nextInt();
			A[i][1]=flip(sc.nextInt(),M);
			if(A[i][0]>A[i][1]) {
				A[i][0]^=A[i][1];A[i][1]^=A[i][0];A[i][0]^=A[i][1];
			}
		}
		Arrays.sort(A,new Comparator<int[]>() {
			@Override
			public int compare(int[] o1, int[] o2) {
				return Long.compare(o1[0], o2[0]);
			}
		});
		int s=0,t=0;
		//[0..s),(M-1-t..M-1]が埋まっている
		for(int i=0;i<N;++i) {
			int ns=s,nt=t;
			boolean left =s<=A[i][0]&&t<=A[i][1];
			boolean right=s<=A[i][1]&&t<=A[i][0];
			if(left&&right) {
				if(s>=t) {
					ns=flip(A[i][1],M)+1;
				}else {
					nt=flip(A[i][1],M)+1;
				}
			}else if(left) {
				ns=flip(A[i][1],M)+1;
			}else if(right) {
				nt=flip(A[i][1],M)+1;
			}
			if((!left&&!right)||s>ns||t>nt||ns-1>M-1-nt) {
				System.out.println("NO");
				return;
			}
			s=ns;t=nt;
		}
		System.out.println("YES");
	}

	
	
	static void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}

}
	
	
class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    private void skipUnprintable() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;}
    public boolean hasNext() { skipUnprintable(); return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    
    public int nextInt() {
    	return (int)nextLong();
    }
}