First of all, one of the managers called me and talked about my skills and experience, as well as my future plans. Then I got an email with a link to do a technical assessment, which consisted of two parts: a critical thinking part and a coding part.

The critical thinking part had 20 reasoning questions, and the coding part had 4 questions. The whole process would be supervised by a third party with your camera on. You were only allowed to use paper and pen. There was no time limit, and you could write in any language you felt comfortable with, including pseudocode.

Find the happy number.