Firm - Working Project / Math.ceil/floor Java Basics

package com.company;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);

        int neededWorkingHours = Integer.parseInt(input.nextLine());
        int daysForTheProject = Integer.parseInt(input.nextLine());
        int overtimeWorkingMan = Integer.parseInt(input.nextLine());

        double educationTime = daysForTheProject * 0.10;
        double timeForTheProject = daysForTheProject - educationTime;
        double hoursForWork = timeForTheProject * 8;
        double overtimeWorkingHours = overtimeWorkingMan * (2 *daysForTheProject);
        double totalHours = overtimeWorkingHours + hoursForWork;

        double diff = totalHours - neededWorkingHours;
        if (diff >= 0) {
            System.out.printf("Yes!%d hours left.", (int) Math.floor(diff));
        } else if (diff < 0) {
            System.out.printf("Not enough time!%d hours needed.", (int) Math.abs(Math.floor(diff)));
        }
    }
}