class Dog{
  public double weight;
  public int age;
  public void eat(){
    weight += 0.1;
  }
}
class Hoge{
	public static void main(String[] args){
		Dog pochi;
		pochi=new Dog();
		pochi.weight=10.0;
		pochi.age=5;
        System.out.println(pochi.weight);
        pochi.eat();
        System.out.println(pochi.weight);
	}
}