An input p(t) = sin(t) is applied to the system G(s) = $\frac{s-1}{s+1}$. The corresponding steady state output is y(t) = sin(t + $\varphi$), where the phase $\varphi$ (in degrees), when restricted to 0$^o$ $\leq$ $\varphi$ $\leq$ 360$^o$, is $\_\_\_\_\_\_$