#include <iostream>
class PureAbstract {
 public:
    virtual void method() = 0;
};
void PureAbstract::method() { std::cout << "Hi from abstract\n"; }

class Derived : public PureAbstract {
 public:
    virtual void method() { PureAbstract::method(); }
};

int main() {
    Derived d;
    d.method();
}