| − | Creates a city (a vertex) with the specified name, coordinates, radius, and color (the last two attributes will be used in later project parts). A city can be successfully created if its name is unique (i.e., there isn't already another city with the same name) and its coordinates are also unique (i.e., there isn't already another city with the same '''(x,y)''' coordinate). Names are case-sensitive.
| + | Prints the AVL-G Tree. |