#include<iostream>
using namespace std;

class customer{
    public:
    void cname(string name){
        cout<<nmae<<" ";
        
    }
};
class meter{
    public:
    int units(int unit){
        return unit;
        
    }
};
class bill:public customer,public meter{
    public:
    void total(int u){
        int unit = units(u)
        int t = unit*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;
    
    
}