Let $f: R \rightarrow R$ and $g \mid: R \rightarrow R$ be defined as $$ \begin{aligned} & f(x)=\left\{\begin{array}{ll} x+a, & x<0 \\ |x-1|, & x \geq 0 \end{array}\right. \text { and } \\ & f(x)=\left\{\begin{array}{ll} x+1, & x<0 \\ (x-1)^2+b & x \geq 0 \end{array}\right. \text { and } \end{aligned} $$ Where $\mathrm{a}, \mathrm{b}$ are non - negative real numbers. If (gof)(x) is continuous for all $\mathrm{x} \in \mathrm{R}$. then $\mathrm{a}+\mathrm{b}$ is equal to $\_\_\_\_$ .