Urban environment analysis

How to make buildings that do not have information about the height and levels randomly assign the number of levels?

Test1.gh (21.1 KB) map (2).rar (342.8 KB)
Now those buildings that do not have level data are equal to 4.5 meters

Essentially, what’s happening is that an empty branch, when multiplied by 4.5, gets assigned the value 4.5, right? This seems like some multiplication bug, although apparently unrelated to it being urban analysis or something else.

the value “1” is assigned to the empty branch - this is the number of levels and then multiplied by 4.5. I need a random branch to have levels that will be multiplied by 4.5