codeforce - Balanced Team

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define MX 1e9+5
int main()
{
    int n,i,cnt=1,res=1;
    scanf("%d",&n);
    int ara[n+1],j;
    for(i=0;i<n;i++)scanf("%d",&ara[i]);
    sort(ara,ara+n);
    i=0,j=1;
    int x=ara[i];
    while(j<n)
    {
        if(ara[j]-x<=5)
        {
            cnt++;

           // cout<<ara[j]-x<<" "<<cnt<<endl;
            j++;
        }
        else
        {
            i++;

            cnt-=1;
            if(i==n)break;
            x=ara[i];
        }
        if(cnt>res)res=cnt;
    }
    printf("%d\n",res);
}