First output is 0

Hi there,

I just started using HS and pretty much thought I understood the principle. However, even the simplest iteration process always has 0 as the first output after resetting HS. What am I doing wrong?

Example attached. The starting value is compared to "y". Because it is bigger, is being lowered by the step "z". However, because F is not S in the beginning, the whole thing doesnt even work...