#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#define INF 2000000000
using namespace std;

int a[103];

int main() {
    int n,i,minim,maxim,j,sol;
    cin>>n;
    for(i=1;i<=n;++i)
        cin>>a[i];
    sort(a+1,a+n+1);
    maxim=INF;
    minim=-INF;
    sol=0;
    for(i=1;i<=n;++i)
    {
        maxim=-INF;
        minim=INF;
        for(j=i;j<=n;++j)
        {
            minim=min(minim,a[j]);
            maxim=max(maxim,a[j]);    
            if(maxim-minim>1)
                j=n+1;
            else
                sol=max(sol,j-i+1);
        }
    }
    cout<<sol<<"\n";
    return 0;
}