Find the real numbers $\displaystyle x_1 ,x_2 ,x_3 ,x_4 ,x_5 $$\displaystyle

$solutions this system, when m is the real parametr :

$\displaystyle \left\{ \begin{array}{l}

x_5 + x_2 = mx_1 \\

x_1 + x_3 = mx_2 \\

x_2 + x_4 = mx_3 \\

x_3 + x_5 = mx_4 \\

x_4 + x_1 = mx_5 \\

\end{array} \right.$