public class A {
   private int x;
   private int y;
 
   public A(int a, int b) {
      x = a;
      y = b;
    }

    public static void main(String[] args) {
       System.out.println("Hi, I'm main.. and I'm going to call f1");
       f1();
       f2(3, 4);
       f3(4, 5);
       f4();
       f5();
    }

    public static void f1() {
       System.out.println("I'm f1...");
       System.out.println("I'm still f1...");
       System.out.println("I'm still f1...");
    }

    public static int f2(int a, int b) {
       return a + b;
    }

    public static A f3(int a, int b) {
       A obj = new A(a, b);
       obj.reset();
       return obj;
    }

    public static void f4() {
        System.out.println("I'm f4 ");
    }

    public static void f5() {
        A a = new A(5, 6);
  
        synchronized(a) {
           System.out.println("I'm f5, accessing a's fields " + a.x + " " + a.y);
        }
    }

    private void reset() {
        x = 0;
        y = 0;
    }
}