// Mammal.java

public class Mammal{
   private int age;
   private double weight;
   Mammal(double weight, int age){
       this.age = age;
       this.weight = weight;
   }
   public double getWeight(){
       return weight;
   }
   public int getAge(){
       return age;
   }
}

// Human.java

public class Human extends Mammal{
   double height;
   Human(double h, double w, int a) {
       super(w, a);
       height = h;
   }
   double getHeight(){
       return height;
   }
}

// Student.java

public class Student extends Human{
   String major;
   double gpa;
   int creditHours;
   Student(String m, double g, int ch, double h, double w, int a){
       super(h, w, a);
       major = m;
       gpa = g;
       creditHours = ch;
   }
   String getMajor(){
       return major;
   }
   double getGpa(){
       return gpa;
   }
   String getYear(){
       if(creditHours < 32) return "Freshman";
       else if(creditHours < 64) return "Sophomore";
       else if(creditHours < 96) return "Junior";
       else return "Senior";
   }
}

// Doctor.java

public class Doctor extends Human{
   int years;
   String Speciality;
   Doctor(int y, String s, double h, double w, int a){
       super(h, w, a);
       years = y;
       Speciality = s;
   }
   int getYears(){
       return years;
   }
   String getSpecialty(){
       return Speciality;
   }
   double getSalary(){
       return 40000 + (years - 1) * 5000;
   }
}

// Lab4.java

public class Lab4{
   public static void main(String args[]){
       Student alex = new Student("CS", 3.4, 54, 170, 150, 18);
       Doctor jack = new Doctor(4, "Dermatology", 173, 179, 40);
       System.out.println(alex.getMajor() + ", " + alex.getGpa() + ", " + alex.getYear() + ", " + alex.getAge());
       System.out.println(jack.getSpecialty() + ", " + jack.getHeight() + ", " + jack.getWeight() + ", " + jack.getSalary());

   }
}

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