#include<bits/stdc++.h>
using namespace std;
#define ll long long
int main()
{
     ll n;
     cin>>n;
     ll arr[n];
     for(int i=0;i<n;i++)
     cin>>arr[i];
     sort(arr,arr+n);
     ll i=0,ans=0;
     while(i<n)
     {
        int j=upper_bound(arr,arr+n,arr[i]+1)-arr;
        if(ans<j-i)
        ans=j-i;
        i++;
     }
     cout<<ans;
}