using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Collections.Generic;
using System.Diagnostics;
using System.Numerics;
using Enu = System.Linq.Enumerable;

public class Program
{
    public void Solve()
    {
        int N = Reader.Int(), W = Reader.Int();
        int[] L = new int[N], R = new int[N];
        for (int i = 0; i < N; i++) { L[i] = Reader.Int(); R[i] = Reader.Int() + 1; }
        var uf = new UnionFind(N * 2);

        for (int a = 0; a < N; a++)
            for (int b = a + 1; b < N; b++)
            {
                bool intersect1 = Intersect(L[a], R[a], L[b], R[b]);
                bool intersect2 = Intersect(W - R[a], W - L[a], L[b], R[b]);
                if (intersect1 && intersect2) { Console.WriteLine("NO"); return; }
                if (intersect1)
                {
                    uf.Unite(a, N + b);
                    uf.Unite(N + a, b);
                }
                if (intersect2)
                {
                    uf.Unite(a, b);
                    uf.Unite(N + a, N + b);
                }
            }
        bool ok = Enu.Range(0, N).All(a => !uf.Same(a, N + a));
        Console.WriteLine(ok? "YES" : "NO");
        Console.ReadLine();
    }

    bool Intersect(int L1, int R1, int L2, int R2)
    {
        return !(R1 <= L2 || L1 >= R2);
    }


    class UnionFind
    {
        private int[] parent;
        private int[] rank;
        private int[] numElements;

        public UnionFind(int N)
        {
            parent = new int[N];
            rank = new int[N];
            numElements = new int[N];
            for (int i = 0; i < N; i++)
            {
                parent[i] = i;
                numElements[i] = 1;
            }
        }
        public int Root(int x)
        {
            if (parent[x] == x) return x;
            return parent[x] = Root(parent[x]);
        }
        public bool Same(int x, int y)
        {
            return Root(x) == Root(y);
        }
        public int NumElements(int x)
        {
            return numElements[Root(x)];
        }
        public bool Unite(int x, int y)
        {
            x = Root(x); y = Root(y);
            if (x == y) return false;
            if (rank[x] > rank[y]) { var t = x; x = y; y = t; }
            if (rank[x] == rank[y]) rank[y]++;
            parent[x] = y;
            numElements[y] += numElements[x];
            return true;
        }
        public Dictionary<int, List<int>> Components()
        {
            var dic = new Dictionary<int, List<int>>();
            for (int i = 0; i < parent.Length; i++)
            {
                int root = Root(i);
                if (!dic.ContainsKey(root)) dic[root] = new List<int>();
                dic[root].Add(i);
            }
            return dic;
        }
    }
}


class Entry { static void Main() { new Program().Solve(); } }
class Reader
{
    static TextReader reader = Console.In;
    static readonly char[] separator = { ' ' };
    static readonly StringSplitOptions op = StringSplitOptions.RemoveEmptyEntries;
    static string[] A = new string[0];
    static int i;
    static void Init() { A = new string[0]; }
    public static void Set(TextReader r) { reader = r; Init(); }
    public static void Set(string file) { reader = new StreamReader(file); Init(); }
    public static bool HasNext() { return CheckNext(); }
    public static string String() { return Next(); }
    public static int Int() { return int.Parse(Next()); }
    public static long Long() { return long.Parse(Next()); }
    public static double Double() { return double.Parse(Next()); }
    public static int[] IntLine() { return Array.ConvertAll(Split(Line()), int.Parse); }
    public static int[] IntArray(int N) { return Range(N, Int); }
    public static int[][] IntTable(int H) { return Range(H, IntLine); }
    public static string[] StringArray(int N) { return Range(N, Next); }
    public static string[][] StringTable(int N) { return Range(N, () => Split(Line())); }
    public static string Line() { return reader.ReadLine().Trim(); }
    static T[] Range<T>(int N, Func<T> f) { return Enu.Range(0, N).Select(i => f()).ToArray(); }
    static string[] Split(string s) { return s.Split(separator, op); }
    static string Next() { CheckNext(); return A[i++]; }
    static bool CheckNext()
    {
        if (i < A.Length) return true;
        string line = reader.ReadLine();
        if (line == null) return false;
        if (line == "") return CheckNext();
        A = Split(line);
        i = 0;
        return true;
    }
}