class Base {
public:
virtual void method() = 0;
};
class Derived1 : public Base{
public:
virtual void method() override { }
};
class Derived2 : public Base{
public:
void method() override { }
};
int main() {}
Y2xhc3MgQmFzZSB7CnB1YmxpYzoKICAgIHZpcnR1YWwgdm9pZCBtZXRob2QoKSA9IDA7Cn07CgpjbGFzcyBEZXJpdmVkMSA6IHB1YmxpYyBCYXNlewpwdWJsaWM6CiAgICB2aXJ0dWFsIHZvaWQgbWV0aG9kKCkgb3ZlcnJpZGUgeyB9Cn07CgpjbGFzcyBEZXJpdmVkMiA6IHB1YmxpYyBCYXNlewpwdWJsaWM6CiAgICB2b2lkIG1ldGhvZCgpIG92ZXJyaWRlIHsgfQp9OwoKaW50IG1haW4oKSB7fQ==