Korisničko ime-rešenje

 #include <iostream>
#include<string>
#include<math.h>

using namespacestd;

int main()
{
string username;                    
cin>> username;                                                                                     //User enters his username
int X;
    X=username.length();                                                                          // Length of user name
if(X<=6){
cout<<"No username created. You miss"<<fabs(X-7)<<" letters."<<endl;
    }
else if(X>=14){
cout<<"No user name created. You have  "<<X-13<<" more letters ."<<endl;
    }
else{
cout<<"Created a username for the user"<<username<<"."<<endl;
    }
return 0;
}