Balanced Team - CodeForces 1133C

/* dpw4112001 */

#include<bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define MOD 1000000007
#define f first
#define i insert
#define all(x) x.begin(),x.end()
#define s second
#define pb push_back
#define MX 1000005
#define IO ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)

int32_t main()
{IO;
    int t=1;
    //cin >>t ;
    while(t--)
    {
        int n;cin >> n;
     
        int a[n+1];
        for(int i=1;i<=n;i++)cin >> a[i];
        sort(a+1,a+n+1);
        int iptr=1;
        int jptr=2;
        int mx_sz=1;
        while(jptr<=n)
        {
           if((a[jptr]-a[iptr])<=5)
           {
               mx_sz=max(mx_sz,jptr-iptr+1);
               jptr++;
           }
           else
           {
               iptr++;
           }
        }
        cout<<mx_sz<<'\n';
    }

    return 0;
}