If $g(x)=1+x-[x]$ where $[x]$ is greatest integer $x$ and $f(x)=\left\{\begin{array}{111}-1,\:\:\:\:x<0\\0,\:\:\:\:\:x=0\\1,\:\:\:\:\:x>0\end{array}\right.$ then $fog(x)=?$

Question

$\begin{array}{1 1} -1 \\ 0 \\ 1 \\ f(x) \end{array}$