/* a tricky mutual recursion */
public class mainer {
  public static void main(String [] args) {
   foo f = new foo();
   f.a();
   System.out.println("done.");
   }
  }
class foo {
  public boolean x = false;
  public foo() {}
  public inline void a() {
   System.out.println("a");
   if (x) {
     a();
     b();
     }
   }
  public inline void b() {
   System.out.println("b");
   if (x) a();
   }
  }