#include <iostream>
#include <stdexcept>
 
class Bird {
public:
    virtual void fly() {
        std::cout << "Flying" << std::endl;
    }
};
 
class Sparrow : public Bird {
public:
    void fly() override {
        std::cout << "Sparrow is flying" << std::endl;
    }
};
 
class Ostrich {
public:
    void walk() {
        std::cout << "Ostrich is walking" << std::endl;
    }
};
 
int main() {
    Bird* bird = new Sparrow();
    bird->fly(); // Correct behavior
 
    // Replacing with Ostrich will cause issues as Ostrich can't fly
    // Bird* ostrich = new Ostrich(); 
 
    delete bird;
    return 0;
}
 
 

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