#include<iostream>
#include<string>
using namespace std;
class customer
{
    protected:
    string name;
    public :
 void display() {
     cin>>name;}};
     class Meter {
         protected:
         int n;
         public:
         void display1(){
             class Bill : public Meter , public Customer {
                 public:
                 void res(){
                     cout<<"Invalid input"<<endl;
                     return;
                 }
                     int total=(n*5)+50;
                     cout<<total<,endl;
                     
                 }
};
int main(){
   Bill b;
   b.display();b.display1();b.res();
return 0; 
}