#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
int main(){
    int n; 
    scanf("%d",&n);
    int *a = malloc(sizeof(int) * n);
    for(int a_i = 0; a_i < n; a_i++){
       scanf("%d",&a[a_i]);
    }
    int max =0,count1,count2;
    for(int i = 0; i <n; i++)
        {
         count1=1;count2=1;
         for(int j=0; j < n;j++){
             
             if(a[j]-a[i] == 1 || a[j] - a[i] == 0 && j != i) count1++;
             else if(a[j]-a[i] == -1 && j != i) count2++;
         }
        if(count1 > count2)
            {
              if(count1 > max) max = count1;
        }
        else
            {
                if(count2 > max) max = count2;
        }
    }
    printf("%d",max);
    return 0;
}