Building Mistakes (polygon)

81 teams scored 1210 points on this task, for a maximum score of 50, an average score of 15 and a median score of 10.

Highlights

  1. Galileo Galilei, Trento is the institute with the most points (90).
  2. Lombardia is the region with the most points (250).

Statement

As building a house is a hard process, you should seriously consider asking an engineer pieces of advice and plans. Despite this, Luca ignored Marco's warnings and decided to try building his house himself. Following the well-known proverb "you cannot build the roof without the floor", he started from building the floor. He was so happy with the newly purchased tiles that he placed all the 100 × 100 tiles, forming a square, even before raising the walls! What a terrible mistake! Now he has to break and throw away some of his tiles in order to raise the planned walls, keeping only those completely inside the house. The original plan of the house has the shape of a polygon and luckily all the vertexes of this polygon coincide with a corner of a tile. How many tiles will survive the raising of the walls?