Please ensure that: Your code is properly formatted as code block - see the sidebar (About on mobile) for instructions You include any and all error messages in full - best also formatted as code block You ask clear questions You demonstrate effort in solving your question/problem - plain posting your assignments is forbidden (and such posts will be removed) as is asking for or giving solutions. If any of the above points is not met, your post can and will be removed without further warning. Code is to be formatted as code block (old reddit/markdown editor: empty line before the code, each code line indented by 4 spaces, new reddit: https://imgur.com/a/fgoFFis ) or linked via an external code hoster, like pastebin.com, github gist, github, bitbucket, gitlab, etc. Please, do not use triple backticks (```) as they will only render properly on new reddit, not on old reddit. Code blocks look like this: public class HelloWorld { public static void main(String[] args) { System.out.println("Hello World!"); } } You do not need to repost unless your post has been removed by a moderator. Just use the edit function of reddit to make sure your post complies with the above. If your post has remained in violation of these rules for a prolonged period of time (at least an hour), a moderator may remove it at their discretion. In this case, they will comment with an explanation on why it has been removed, and you will be required to resubmit the entire post following the proper procedures. To potential helpers Please, do not help if any of the above points are not met, rather report the post. We are trying to improve the quality of posts here. In helping people who can't be bothered to comply with the above points, you are doing the community a disservice. I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns. More on reddit.com

I think you can probably figure this one out just with a hint.

What happens to negative numbers when they are multiplied by -1?

Note that you can check if numbers are less than zero using if and then do something about less than zero numbers.

If you still get stuck after thinking on that for a few minutes shoot me a pm.

Edit: as long as you don't ask me to just write out all the code for you.

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I'm pretty new to java myself, but doesn't Math.abs return the absolute value, so it returns negative numbers as positive? I'd have gone with else if (18 < age > 24) More on reddit.com

java still thinks that it's getting a negative number No, it doesn't. The exception that you are getting says "n must be positive," right? The problem is not that you are giving it a negative number. The problem is that you are giving it a nonpositive number: you're giving it the number 0. More on reddit.com