Die.java

import java.util.Random;

public class Die {
    private int top;
    private Random rnd;

    public Die() {
        rnd = new Random();
        top = 1 + rnd.nextInt(6);
    }

    public void roll() {
        top = 1 + rnd.nextInt(6);
    }

    public int getNum() {
        return top;
    }
}