#include<iostream>
using namespace std;
class customer{
  
    public :
    void setName(string name){
        cout<<name<<"";
        
    }
};
class Meter{
    public:
    int units(int unit){
        return unit;
    }
};
class Bill:public customer,public Meter{
    public:
    void total(int u){
        int unit = unit(u);
        int t= (units*5) + 50;
        cout<<t<<endl;
        
    }
};
int main()
{
    string name;
    int units;
    cin>>name>>units;
    if(units<0){
        cout<<"invalid input";
        return 0;
    }
   Bill obj;
   obj.cName(name);
   obj.total(units);
   return 0;
}