#include
#include
using namespace std;
class Base
{
public:
virtual int add(int a, int b) { return(a + b); };
virtual int sub(int a, int b) { return(a - b); };
virtual int mult(int a, int b) { return(a * b); };
};
class ShowMath : public Base
{
virtual int mult(int a, int b)
{
cout << a * b << endl;
return(a * b); };
};
class PositiveSubt : public Base
{
virtual int sub(int a, int b) { return(abs(a - b)); };
};
int main(void)
{
Base *poly = new ShowMath;
cout << poly->add(562, 531) << ' ' << poly->sub(1500, 407) << endl;
poly->mult(1093, 1);
poly = new PositiveSubt;
cout << poly->add(892, 201) << ' ' << poly->sub(0, 1093) << endl;
cout << poly->mult(1, 1093);
}