What's wrong? Please help!

Your main problem, which most likely ruins everything, is that you take in input two times. The test is most likely sending a single number for each test, which get picked up by the first variable, and saved as a string. This is where the numbers sent by the test gets stored, and since the variable is never used in your code, and of the wrong type, it will invalidate all test conditions untill fixed. Try to work with only a single variable either by: BufferedReader reader = new BufferedReader(new InputStreamReader(System.in); int num = Integer.parseInt(reader.nextLine()); or Scanner scanner = new Scanner(System.in); int num = scanner.nextInt(); You also need to fix this, in order to make the test pass: Condition 2. "The program must display a number on the screen." = If the number is 0, your program displays a string("zero") on the screen instead of the number 0. Hint: Since you are only using the scanner and the bufferedreader a single time, you don't really need to store the object you are creating in a variable, and can simply do this: int num = Integer.parseInt(new BufferedReader(new InputStreamReader(System.in)).nextLine()); or int num = new Scanner(System.in).nextInt(); Good luck! :)

It's a few things - first you are declaring BufferedReader in a weird way. Second why do you need the two extra String variables? I don't see what they do. Third you can simplify your code in the ifs:

public static void main(String[] args) throws Exception {
           //write your code here
           BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

           int number1 = Integer.parseInt(bufferedReader.readLine());

           if (number1 > 0) {
               number1 *= 2;
               System.out.println(number1);
           } if (number1 < 0) {
               number1 += 1;
               System.out.println(number1);
           } if (number1 == 0) {
               System.out.println("zero");
           }

       }

   }