Uno.java

public abstract class Uno {
    private int a;
    private int b;

    public Uno() {
        this.a = 0;
        this.b = 0;
    }

    public int get_a() {
        return a;
    }

    public int get_b() {
        return b;
    }

    abstract public int mayor(int a, int b);
    abstract public int menor(int a, int b);
}