C-Balenced Team

////////////////          PRANTA KUMER PANDIT            ///////////////
//                      Test Case Less Template                       ||
//                                                                    ||
//                                                                    ||
//      BANGLADESH  UNIVERSITY OF BUSINESS AND TECHNOLOGY             ||
//                          INTAKE 52                                 ||
//                      DEPARTMENT OF CSE                             ||
//                                                                    ||
//||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
//                      So, WELCOME TO ISHAN'S PERADISE           //
//                (-.-) Want to be a Secret tool of next ICPC��(-.-)����//
 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb   push_back
#define yes   cout<<"YES"<<endl
#define no   cout<<"NO"<<endl
#define all(x) (x).begin(), (x).end()
#define    gcd(a,b)      __gcd(a,b)
#define    lcm(a,b)  (a*b)/__gcd(a,b)
#define optimize() ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//void solve(){
int32_t main() {
    optimize();
    int n;
    cin >> n;
    vector<int> a(n);
    for (int &x : a) cin >> x;
sort(all(a));
    int m = 0, left = 0;
    for (int right = 0; right < n; right++) {
        while (a[right] - a[left] > 5) {
            left++;
        }
        m = max(m, right - left + 1);
    }
    cout << m << "\n";
    return 0;
}
//                                   THANKS������������   ��������������//