Statement

After solving the black hole equations, Giorgio has patented a brand-new project for a teleport machine. This handy device would approximately resemble a photo booth, and allow customers to be instantly dematerialized and then fully reassembled into a perfectly functional human being, in another teleport machine of their choice. Since there are no known side effects as of now, Giorgio is enthusiastic about his new project and cannot wait to realize it. However, building a teleport machine is pretty expensive (and definitely out of his budget): so it is time to get a sponsor! Giorgio laid out a map of the city of Torino, consisting of streets, buildings and the proposed teleport machines. This map is a grid of H × W characters C_ij, which can be either: (1) `.' to represent a street, square or any other open space in the city; (2) `#' to represent a building, river or any other obstacles; (3) `@' to represent a teleport machine; (4) `C' to represent the city hall...