using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static long NN => long.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, h) = (c[0], c[1]);
        var map = NArr(n);
        var list = new List<(int time, int value)>();
        for (var i = 0; i < n; ++i)
        {
            list.Add((map[i][0], 1));
            list.Add((map[i][1], 2));
        }
        list.Sort((l, r) =>
        {
            var d = l.time.CompareTo(r.value);
            if (d != 0) return d;
            return l.value.CompareTo(r.value);
        });
        var ans = 0;
        var tmp = 0;
        foreach (var info in list)
        {
            if (info.value == 1) ++tmp;
            else --tmp;
            ans = Math.Max(ans, tmp);
        }
        WriteLine(ans);
    }
}