pls what's wrong with my code
package com.codegym.task.task06.task0621;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
/*
Cat relations
*/
public class Solution {
public static void main(String[] args) throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String GrandfatherName = reader.readLine();
Cat catGrandfather =new Cat(GrandfatherName);
String GrandmotherName = reader.readLine();
Cat catGrandmother = new Cat(GrandmotherName);
String fatherName = reader.readLine();
Cat catFather = new Cat(fatherName, catGrandfather,null);
String motherName = reader.readLine();
Cat catMother = new Cat(motherName, catGrandmother, null);
String sonName = reader.readLine();
Cat catSon = new Cat(sonName, catFather, catMother );
String daughterName = reader.readLine();
Cat catDaughter = new Cat(daughterName, catMother, catFather);
System.out.println(catGrandfather);
System.out.println(catGrandmother);
System.out.println(catFather);
System.out.println(catMother);
System.out.println(catSon);
System.out.println(catDaughter);
}
public static class Cat {
private String name;
// private Cat parent;
private Cat father;
private Cat mother;
Cat(String name) {
this.name = name;
}
Cat(String name, Cat father, Cat mother) {
this.name = name;
this.father = father;
this.mother = mother;
}
@Override
public String toString() {
if (mother == null && father != null)
return "The cat's name is " + name + ", no mother "+ this.father.name+ " is the father";
else if (father == null && mother != null)
return "The cat's name is " + name + ",no father " + this.mother.name + " is the mother";
else if (father != null && mother != null)
return "The cat's name is " + name + ", "+ this.father.name + " is the father"+ ","+ this.mother.name+ " is the mother";
else
return "The cat's name is " + name + ","+ " no mother, no father";
}
}
}