PolandBall convex polygon n veritce diagonal intersect point PolandBall decide improve draw red segment he choose number k gcdnk1 Vertices polygon number 1 n clockwise way PolandBall repeat follow process n time start vertex 1 assume you ve end operation vertex x consider x1 operation draw new segment vertex x kth vertex clockwise direction this vertex xk xkn depend valid index polygon vertexyour task calculate number polygon section draw a section clear area inside polygon bound draw diagonal polygon side