Remote Training on Programming

Maintenance department of H&H company bought a new table. Table has a square form. For a strange reason network patchcords at the H&H company stick out from the floor at the points with integer coordinates (what is even more strange each point with an integer coordinates has a patchcord).

Maintenance department manager asked you to help to find out the minimum possible number of patchcords covered by the table. Patchcords is covered by the table if it lays strictly inside the square perimeter of bottom surface of the table.