text: #pragma once
  #include <iostream>
  
  template<typename T = double>
  struct Difference
  {
  	template<typename ... Ts>
  	void leftToRight(Ts ... args){
  		value =  (... - args);
  	}
  
  	template<typename ... Ts>
  	void leftToRightFromZero(Ts ... args){
  		value = (0 - ... - args);
  	}
  
  	friend std::ostream& operator<<(std::ostream& os, const Difference& to_print){
  		os<<to_print.value;
  		return os;
  	}
  
  private:
  	T value;
  };