Прошу помощи

package com.javarush.task.task06.task0621; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; /* Родственные связи кошек */ public class Solution { public static void main(String[] args) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String grandFatherName = reader.readLine(); // String grandFatherName = "дедушка Вася"; Cat catGrandFather = new Cat(grandFatherName); String grandMotherName = reader.readLine(); // String grandMotherName = "бабушка Мурка"; Cat catGrandMother = new Cat(grandMotherName); String fatherName = reader.readLine(); // String fatherName = "папа Котофей"; Cat catFather = new Cat(fatherName, catGrandFather); String motherName = reader.readLine(); // String motherName = "мама Василиса"; Cat catMother = new Cat(motherName, catGrandMother); String sonName = reader.readLine(); // String sonName = "сын Мурчик"; Cat catSon = new Cat(sonName, catFather , catMother); String daughterName = reader.readLine(); // String daughterName = "дочь Пушинка"; Cat catDaughter = new Cat(daughterName, catFather , catMother); System.out.println(catGrandFather); System.out.println(catGrandMother); System.out.println(catFather); System.out.println(catMother); System.out.println(catDaughter); System.out.println(catSon); } public static class Cat { private static int catcount = 0; private int catnum; private String name; private Cat mother; private Cat father; private Cat grabdfather; private Cat grandmother; private Cat son; private Cat daughter; Cat(String name) { this.name = name; catcount++; this.catnum = catcount; } Cat(String name, Cat grabdfather) { switch (catcount){ case 2: this.name = name; this.father = grabdfather; this.mother = null; break; case 3: this.name = name; this.father = null; this.mother = grabdfather; break; } catcount++; } Cat(String name, Cat p1, Cat p2) { this.name = name; this.father = p1; this.mother = p2; } @Override public String toString() { if (mother == null && father != null) return "Cat name is " + name + ", no mother, father is " + father.name; else if (mother != null && father == null) return "Cat name is " + name + ", mother is " + mother.name + ", no father"; else if (catnum == 1) return "Cat name is " + name + ", no mother, no father"; else if (catnum == 2) return "Cat name is " + name + ", no mother, no father"; else if (catcount == 3) return "Cat name is " + father.name + ", no mother, father is " + grabdfather.name; else return "Cat name is " + name + ", mother is " + mother.name + ", father is " + father.name; } } }