#include <iostream>
using namespace std;
class Customer
{
    public:
    void Name(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 = 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.name(name);
    obj.total(units);
    return 0;
}