package no274;

import java.util.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		System.out.println(new Main().solve() ? "YES" : "NO");
	}

	int m;

	public boolean solve() {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		m = sc.nextInt();
		Block[] b = new Block[n];
		for(int i=0;i<n;i++) {
			b[i] = new Block(sc.nextInt(),sc.nextInt());
		}
		Arrays.sort(b);
		int l = 0;
		int r = m-1;
		for(int i=0;i<n;i++) {
			int bl = b[i].l;
			int br = b[i].r;
			if (l <= bl) {
				if (br > r) {
					return false;
				}
				l = br + 1;
			}else{
				bl = m - 1 - bl;
				br = m - 1 - br;
				if (l <= bl && br <= r) {
					r = bl - 1;
				}else{
					return false;
				}
			}
		}
		return true;
	}

	class Block implements Comparable<Block>{
		int l,r;
		public Block(int l,int r) {
			if (l <= m-1-r) {
				this.l = l;
				this.r = r;
			}else{
				this.l = m - 1 - r;
				this.r = m - 1 - l;
			}
		}
		public int compareTo(Block o) {
			if (l != o.l) {
				return Integer.compare(l, o.l);
			}
			return Integer.compare(r, o.r);
		}
		public String toString() {
			return "[" + l + "," + r + "]";
		}
	}

}