Нужна подсказка по коду, что доделать или переделать

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 grandmotherName = reader.readLine();
        Cat catGrandmother = new Cat(grandmotherName);

        String grandfatherName = reader.readLine();
        Cat catGrandfather = new Cat(grandfatherName);

        String motherName = reader.readLine();
        Cat catMother = new Cat(motherName, catGrandmother);

        String fatherName = reader.readLine();
        Cat catFather = new Cat(fatherName, catGrandfather);

        String daughterName = reader.readLine();
        Cat catDaughter = new Cat(daughterName, catMother, catFather);

        String sonName = reader.readLine();
        Cat catSon = new Cat(sonName, catMother, catFather);

        System.out.println(catGrandmother);
        System.out.println(catGrandfather);
        System.out.println(catMother);
        System.out.println(catFather);
        System.out.println(catDaughter);
        System.out.println(catSon);
    }

    public static class Cat {
        private String name;
        private Cat parent1;
        private Cat parent2;

        Cat(String name) {
            this.name = name;
        }

        Cat(String name, Cat parent1) {
            this.name = name;
            this.parent1 = parent1;
        }

        Cat(String name, Cat parent1, Cat parent2) {
            this.name = name;
            this.parent1 = parent1;
            this.parent2 = parent2;
        }

        @Override
        public String toString() {
            if (parent1 == null && parent2 == null)
                return "Cat name is " + name + ", no mother " + ", no father ";
            else {
                if (parent1.name.contains("папа"))
                    return "Cat name is " + name + ", no mother" + ", father is " + parent1.name;
                else if (parent1.name.contains("мама"))
                    return "Cat name is " + name + ", mother is " + parent1.name + ", no father ";
                else
                    return "Cat name is " + name + ", mother is " + parent1.name + ", father is " + parent2.name;
            }
        }
    }

}