Let two vertices of a triangle ABC be (2,4,6) and (0,-2,-5) , and its centroid be (2,1,-1). If the image of the third vertex in the plane $x+2y+4z=11$ is $(\alpha ,\beta ,\gamma ),$ then $\text{α + β + γ\hspace{0.17em} is\_\_\_\_\_\_\_\hspace{0.17em}}$