\bigl|u^{-1}[\{s\}]\bigr|=\left\{\begin{array}{ll}0,&\hbox{za }\frac 1 e<s\\1,&\hbox{za }s\leq 0\hbox{ ili }s=\frac 1 e\\2,&\hbox{za }0<s<\frac 1 e\end{array}\right.