Add rounding up to the description (1.55 = 2)

I have been solving this problem for two days. I've tried a lot of options. And yes! It started working in the development environment. And here (For input string: "") Added even a null exception and NOTHING! What did I leave out or is it not a complete description of what should be when entering an empty string.

I just came up with something))

Doesn't work in Kotlin (sqrt). rounding does not follow the rules of mathematics