#include <iostream>
#include<cmath>
#include<algorithm>

using namespace std;

int main()
{
int n ;
cin>>n;
int a[n];
for(int i = 0 ; i < n ; i++){
    cin>>a[i];
}
int maxa = 0 ;
for( int i = 0  ; i < n  ; i++)
{
    int local1 =  0;
    int local2 =  0 ;
    for( int j = 0 ; j  < n ; j++){
       if( a[i] - a[j] <= 0 && a[i] - a[j] >= 0 )
            local1++ ;
          if( a[i] - a[j] >= 0 && a[i] - a[j] <= 1 )
            local2++ ;
  }



       if (max(local1,local2) > maxa)
    maxa = max(local1,local2) ;
}




cout<<maxa   ;
    return 0;
}