class Dolog {
	int szam = 1;
}
class Program01 {	
	public static void szamol(Dolog dolog) {
		dolog.szam = dolog.szam * 2;
		System.out.println(dolog.szam);
	}
	
	public static void main(String[] args) {
		Dolog dolog = new Dolog();
		dolog.szam = 4;
		szamol(dolog);
		System.out.println(dolog.szam);
	}
}