2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/173222We associate to a good cell decomposition of a manifold M a quadratic algebra and show that the Koszulity of the algebra implies a restriction on the Euler characteristic of M. For a two-dimensional manifold M the algebra is Koszul if and only if the Euler characteristic of M is two.Latex, 20 pages, one figureRings and AlgebrasAlgebraic Topology16S37; 57M20; 57M60; 55U10text