import java.util.Iterator;
import java.util.Set;

/**
 *
 * @author Paolo
 */
public class A extends B<Object>  {
        private B<?> b;
        private String msg;
        public A(){
            b = new B<Object>(null);
            msg = B.<A>buildMessage(this);
        }
        public Set<? super Number> f(Set<Integer> set1, Set<String> set2) {
            for (Integer n: b)
                if (b.check(set1, n))
                    return b.process(set1, set2, n);
                    return b.process(set2, set1, null);
        }
}

class B<T> implements Iterable<Integer>{

    public boolean check(Set<?> s,int a){
        return s.contains(a);
    }

    public Set<? super Number> process(Set<Integer> s1 ,Set<String> s2 ,Integer n){
        Object o=new Object();
        return (Set<? super Number>) o;

    }

    Set<? super Number> process(Set<String> set2, Set<Integer> set1, Object object) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    public static <T> String buildMessage(T a){
        return "hi";
    }

    public B(){

    }

    B(T object) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

    @Override
    public Iterator<Integer> iterator() {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }






}