using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {

    static void Main(String[] args) {
        int n = Convert.ToInt32(Console.ReadLine());
        string[] a_temp = Console.ReadLine().Split(' ');
        int[] a = Array.ConvertAll(a_temp,Int32.Parse);
        int max=0;
        foreach(var v in a){
            int uc = 0;
            int u = v+1;
            int lc = 0;
            int l = v-1;
            foreach(var vv in a){
                if(vv>v){
                    if(vv<=u)
                        uc++;
                }else if(vv<v){
                    if(vv>=l)
                        lc++;
                }else{
                    uc++;
                    lc++;
                }
            }
            if(max<lc){
                max=lc;
            }
            if(max<uc){
                max=uc;
            }
        }
        Console.WriteLine(max);
    }
    
}