The author of this writeup was doing this task for quite a long time.

The main issue in the challenge was that there was uncovered code in php and there was a `preg_replace()` function being used that would replace the word `bingus` with the empty string `''`. To make matters worse, if the author wanted to get a flag, he had to type that word `bingus`.

After a long time, the author finally created a payload. The answer was quite simple, and it was `binbingusgus`. The string from the middle was removed and the rest of the characters were concatenated together. This made it possible to get a flag.