#include <iostream>
using namespace std;

struct MyQuestion
{
	void fun()
	{ cout<<"a"; }
	
	void fun()const
	{ cout<<"b"; }

	void call()
	{
	    const_this()->fun();   // calls fun() const
	
	    fun();                 // calls fun()
	}

private:
    const MyQuestion *const_this() const {
        return this;
    }
};

int main() {
	MyQuestion q;
	q.call();
}