ошибка при компиляции. что не так?

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 grfatherName = reader.readLine();
        Cat grcatFather = new Cat(grfatherName);

        String grmotherName = reader.readLine();
        Cat grcatMother = new Cat(grmotherName);

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

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

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

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


        System.out.println(grcatFather);
        System.out.println(grcatMother);
        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 mother;
        private Cat father;

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

        Cat(String name, Cat mother, Cat father) {
            this.name = name;
            this.mother = mother;
            this.father = father;

        }

        @Override
        public String toString() {
            if ((mother == null)&&(father == null))
                return "Cat name is " + name + ", no mother, no father ";
            if ((mother != null)&&(father == null))
                return "Cat name is " + name + ", mother is " + mother.name +", no father ";
            if ((mother == null)&&(father != null))
                return "Cat name is " + name + ", no mother, father is " + father.name;
            if ((mother != null)&&(father != null))
            return "Cat name is " + name + ", mother is " + mother.name + "father is " + father.name;

        }
    }

}