#include <iostream>
 
class A {
    public:
		virtual void hoge() {
			std::cout << "A" << std::endl;
		}
};
 
class A1 : public A {
	public:
		void hoge() {
			std::cout << "A1" << std::endl;
		}
};
 
class A2 : public A {
	public:
		void hoge() {
			std::cout << "A2" << std::endl;
		}
};
 
void recieve_a(A pa) {
	pa.hoge();
}
 
int main() {
	A1 a1;
	A2 a2;
 
	recieve_a(a1);	// A1 と表示させたい
	recieve_a(a2);	// A2 と表示させたい
}

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