import java.util.Random;

public class DiceHelper {

    private static final Random rng = new Random();

    public static void main(String[] args) {

    }

    /**
     * Returns the result of rolling a dice with s sides.
     *
     * @param sides     the number of sides on the dice
     * @return          the sum of dice rolled
     */
    public static int roll(int sides) {
        return rng.nextInt(sides) + 1;
    }

    /**
     * Returns the sum of rolling n dice with s sides.
     *
     * @param sides     the number of sides on each dice to roll
     * @param numRolls  the number of dice to roll
     * @return          the sum of dice rolled
     */
    public static int roll(int sides, int numRolls) {
        int sum = 0;
        for(int i = 0; i < numRolls; i++) {
            sum += roll(sides);
        }
        return sum;
    }

    /**
     * Returns the sum of rolling n dice with s sides
     * and adds m to the result of each roll.
     *
     * @param sides     the number of sides on each dice to roll
     * @param numRolls  the number of dice to roll
     * @param modifier  the amount to add to the result of each dice roll
     * @return          the sum of dice rolled
     */
    public static int roll(int sides, int numRolls, int modifier) {
        int sum = 0;
        for(int i = 0; i < numRolls; i++) {
            sum += roll(sides) + modifier;
        }
        return sum;
        // equivalent:
        // return roll(sides, numRolls) + numRolls * modifier);
    }
}