[JAVA] Số Đối Diện

public class SoDoiDien { public static int SoDoiDien(int n) { return n*-1; } public static void main(String[] args) { SoDoiDien a = new SoDoiDien(); Scanner kb = new Scanner(System.in); System.out.println("Nhap mot so: "); int n = kb.nextInt(); System.out.println("So doi dien cua "+n+ " la: "+a.SoDoiDien(n)); } }