Не могу понять, почему не правильно)

package com.javarush.task.task02.task0213; /* Питомцам нужны люди */ public class Solution { public static void main(String[] args) { Woman woman=new Woman(); Cat cat=new Cat(); Dog dog=new Dog(); Fish fish=new Fish(); Cat.owner = new woman; Dog.owner= new woman; Fish.owner= new woman; Woman.owner= new woman; } public static class Cat { public Woman owner; } public static class Dog { public Woman owner; } public static class Fish { public Woman owner; } public static class Woman { } }