#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;


int main(){
    int n;
    cin >> n;
    int a[n],count=0,count1=0,count2=0,max=0;
    for(int a_i = 0;a_i < n;a_i++){
       cin >> a[a_i];
    }
    
    int a_i=0;
   
    while(a_i<n)
      {
                 count1=0;
                 count2=0;
                for(int j=0;j<n;j++)
                {
                if(a[j]-a[a_i]==0 || a[j]-a[a_i]==-1) 
                    {
                        count1++;
                    }
                 if(a[j]-a[a_i]==1 || a[j]-a[a_i]==0)
                     count2++;
                }
        if(count1>count2)
            count=count1;
        else
            count=count2;
        
       
         if(max<count)
             max=count;
        
                a_i++;
                
                
    }
    cout<<max;
    return 0;
}