#include <iostream>
#include <sstream>
#include <string>

int main(int argc, char* argv[])
{
	std::string s = "4 + 5";
	std::istringstream iss;
	iss.str(s);
	
	int a, b;
	iss >> a;
	iss.ignore(10,'+');
	iss >> b;
	
	std::cout << a << std::endl;
	std::cout << b << std::endl;
	std::cout << a + b << std::endl;

	return 0;
}