#include <iostream>
#include <vector>
using namespace std;

class Yoba {
public:
	Yoba(int yobaSize): _size(yobaSize) {};
	friend std::ostream& operator<< (std::ostream& stream, const Yoba& yoba) 
	{
    	stream << "Yoba size: " << yoba._size;
    	return stream;
    }
private:
	int _size;
};

int main() {
	vector<Yoba> yobas { Yoba(3), Yoba(4)};
	for(auto yoba: yobas) {
		cout << yoba << endl;
	}
}