import java.util.ArrayList;
import java.util.List;

public class FilterDemo {
    public static void main(String[] args)
    {
        List<Person> ps=new ArrayList();
        Person p1=new Person(0,"a1");
        Person p2=new Person(0,"a2");
        Person p3=new Person(0,"a3");
        Person p4=new Person(1,"a4");
        Person p5=new Person(0,"a5");
        Person p6=new Person(1,"a6");
        ps.add(p1);ps.add(p2);ps.add(p3);ps.add(p4);ps.add(p5);ps.add(p6);
        Filter f=new FemaleFilter();
        List<Person> result=f.filte(ps);
        for(Person p:result)
        {
            System.out.println(p.name);;
        }
    }
}

interface Filter
{
    List<Person> filte(List<Person> persons);
}
class MaleFilter implements Filter
{
    public List<Person> filte(List<Person> persons){
        List<Person> malePersons=new ArrayList();
        for(Person p:persons)
        {
            if(p.sex==0)
            {
                malePersons.add(p);
            }
        }
        return malePersons;
    }
}

class FemaleFilter implements Filter
{
    public List<Person> filte(List<Person> persons){
        List<Person> femalePersons=new ArrayList<Person>();
        for(Person p:persons)
        {
            if(p.sex==1)
            {
                femalePersons.add(p);
            }
        }
        return femalePersons;
    }
}
class Person
{
    public int sex;
    public String name;
    Person(int sex,String name)
    {
        this.sex=sex;
        this.name=name;
    }
}