Statement

The forty-second edition of the annual robotic ant contest is about to begin. This year, Giorgio is in charge of choosing the test that the participating robots will need to pass in order to win. The previous organizers caused quite a mess last time (who could ever forget the Anteater arena?), for this reason Giorgio decided to go with something easier: he will set up a grid in the guise of a labyrinth (the Labygrid) and he will reward the ant that will traverse it in the most efficient manner. A labygrid is nothing more than a pavement formed by N × M square-shaped tiles. For example, a valid labygrid having N=4 and M=6 can be seen in the following picture: The goal of the robotic ants is to reach the bottom-right corner of the (N-1, M-1) tile starting from the top-left corner of the (0, 0) tile. The hard part is to do that by trying to step on as few tiles as possible. The winning ant is the one that will step on the least number of tiles...