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