#include<iostream>
#include<string>
class Expression
{
public:
	virtual Expression *diff() = 0;
	virtual void print() = 0;

};
class Number : public Expression
{
	int c;
public:
	Number (int r) { c = r; }
	Expression *diff()  override{ return 0; }
	void print()
	{
		std::cout <<c << " ";
	}
};
class Variable : public Expression
{
	std::string *v1;
public:
	Variable( std::string *v)
	{
		v1 = v;
	}
	Expression *diff() override
	{
		return new Variable( v1->diff());
	}
	void print() override
	{
		std::cout << v1->diff <<" " ;
	}

};
class Add : public Expression
{
	Expression *Ex1, *Ex2;
public:
	Add(Expression *u, Expression *v)
	{
		Ex1 = u;
		Ex2 = v;
	}
	Expression *diff( ) override
	{
		return  new Add(Ex1->diff(), Ex2->diff());
	}
	void print() override { std::cout << "(" << Ex1->diff() << "+" << Ex2->diff() << ")"; }

};
class Sub : public Expression
{
	Expression *e1, *e2;
public:
	Sub(Expression *u, Expression *v)
	{
		e1 = u;
		e2 = v;
	}
	Expression *diff() override
	{
		return new Sub(e1->diff(),e2->diff()) ;
	}
	void print() override
	{
		std::cout << "(" << e1->diff() << "-" << e2->diff() << ")";
	}

};

/*class Mul : public Expression
{
	Expression *u, *v;
public:
	Mul(Expression *y, Expression *p) { u = y; v = p; }
	Expression *diff() override
	{
		return new Sub(u*(v->diff()), v*(u->diff()));
	}
	void print() override
	{

		std::cout<<u
	}
};*/
class Div : public Expression
{

};
int main()
{
	int r;
	Expression *e = new Add(new Variable('x'), new Number(1));
	std::cout << "\n";
	Expression *pr = e->diff();
	std::cout << "\n";



	//t.print();
	//a.print();
	std::cin >>r ;




}