using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static string InputPattern = "Input5";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("4 6");
            WillReturn.Add("5 5");
            WillReturn.Add("2 3");
            WillReturn.Add("4 4");
            WillReturn.Add("1 1");
            //YES
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("4 6");
            WillReturn.Add("3 5");
            WillReturn.Add("3 4");
            WillReturn.Add("4 4");
            WillReturn.Add("1 2");
            //NO
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("2 4");
            WillReturn.Add("0 1");
            WillReturn.Add("0 1");
            //YES
        }
        else if (InputPattern == "Input4") {
            WillReturn.Add("5 10");
            WillReturn.Add("8 8");
            WillReturn.Add("0 0");
            WillReturn.Add("2 4");
            WillReturn.Add("2 3");
            WillReturn.Add("8 8");
            //YES
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    struct LRDef
    {
        internal int L;
        internal int R;
    }

    static int M;

    static void Main()
    {
        List<string> InputList = GetInputList();
        int[] wkArr = { };

        Action<string> SplitAct = (pStr) =>
            wkArr = pStr.Split(' ').Select(X => int.Parse(X)).ToArray();

        SplitAct(InputList[0]);
        M = wkArr[1];

        var LRList = new List<LRDef>();
        for (int I = 1; I <= InputList.Count - 1; I++) {
            SplitAct(InputList[I]);
            LRList.Add(new LRDef() { L = wkArr[0], R = wkArr[1] });
        }

        Console.WriteLine(ExecDFS(LRList) ? "YES" : "NO");
    }

    struct JyoutaiDef
    {
        internal int CurrY;
        internal System.Collections.BitArray BanArr;
        //internal string FillLog;
    }

    //深さ優先探索で解の有無を判定する
    static bool ExecDFS(List<LRDef> pLRList)
    {
        var stk = new Stack<JyoutaiDef>();
        JyoutaiDef WillPush;
        WillPush.CurrY = 0;
        WillPush.BanArr = new System.Collections.BitArray(M);
        //WillPush.FillLog = "";
        stk.Push(WillPush);

        while (stk.Count > 0) {
            JyoutaiDef Popped = stk.Pop();

            //クリア判定
            if (Popped.CurrY > pLRList.Count - 1) {
                //Console.WriteLine(Popped.FillLog);
                return true;
            }

            Action<LRDef> PushSyori = (pLR) =>
            {
                for (int I = pLR.L; I <= pLR.R; I++) {
                    if (Popped.BanArr[I]) return;
                }
                WillPush.CurrY = Popped.CurrY + 1;
                WillPush.BanArr = new System.Collections.BitArray(Popped.BanArr);
                for (int I = pLR.L; I <= pLR.R; I++) {
                    WillPush.BanArr[I] = true;
                }
                //WillPush.FillLog = Popped.FillLog + string.Format("{0}から{1}がピンクになります",
                //    pLR.L, pLR.R);
                //WillPush.FillLog += Environment.NewLine;
                stk.Push(WillPush);
            };

            PushSyori(pLRList[Popped.CurrY]);
            PushSyori(DeriveKaitenLR(pLRList[Popped.CurrY]));
        }
        return false;
    }

    //180度回転したLRを返す
    static LRDef DeriveKaitenLR(LRDef pLR)
    {
        int NewL = M - 1 - pLR.R;
        int NewR = M - 1 - pLR.L;
        return new LRDef() { L = NewL, R = NewR };
    }
}