در تابع با ضابطه $f\left( x \right)=\left\{ \begin{matrix}
x-\sqrt{x+4}\,\,\,\,\,\,\,\,\,\,\,\,\,\,x>3 \\
2x+3\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\le 3 \\
\end{matrix} \right.$، مقدار $f\left( f\left( 5 \right) \right)+f\left( f\left( 1 \right) \right)$ کدام است؟