If $z_1, z_2$ are complex numbers such that $\operatorname{Re}\left(z_1\right)=\left|z_1-1\right|, \operatorname{Re}\left(z_2\right)=\left|z_2-1\right|$, and $\arg \left(z_1-z_2\right)=\frac{\pi}{6}$, then $\operatorname{Im}\left(z_1+z_2\right)$ is equal to
