Circle $O$ with radius $16$ is internally tangent to circles $A$, $B$, and $C$. Circles $A$, $B$, and $C$ do not overlap. Circle $C$ has radius $11$ and the radii of circles $A$, $B$, and $C$ (in that order) form an increasing arithmetic sequence. Find the sum of the radii of circles $A$, $B$, and $C$.