import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] arr = new int[n];
        for(int a_i=0; a_i < n; a_i++){
            arr[a_i] = in.nextInt();
        }
        int g[][] = new int[n][n];
        for(int i=0;i<n;i++){
            for(int j=0;j<n;j++){
                g[i][j] = arr[i]-arr[j];
             //   System.out.print(g[i][j]+" ");
            }
            //System.out.println();
        }
        int max=0;
        for(int i=0;i<n;i++){
            int c0=0,cp=0,cn=0;
            for(int j=0;j<n;j++){
                if(g[i][j]==0)
                    c0++;
                if(g[i][j]<0&&g[i][j]>=-1)
                    cn++;
                if(g[i][j]>0&&g[i][j]<=1)
                    cp++;
            }
            //System.out.println(c0+" "+cp+" "+cn+" max = "+max);
            int loop = c0+Math.max(cn,cp);
            max = Math.max(max,loop);
        }
        System.out.println(max);
    }
}