why make a wrong description of the kata? You could just write, remove all the spaces and $ and turn it into a double. If examples like " -$$30 $$$20 $2$ "

The tests pass solutions even for examples like " -$0.$30 $$$0 $2$ ". So don’t rack your brain too much, think simpler. I spent several hours writing out all the impossible options, but it turned out that anything passes in the tests.

This kata is incorrect. The author has never glued wallpaper himself. Having a perimeter, we divide it by the width of one roll and in the end we should get a integer number. Check the solution on the data l = 0.1, w = 0.1, h = 11.0. according to the decision of the author, one roll will be enough for us, but here it is clearly visible that the height of the apartment is 11 meters.