  Pipedreams are combinatorial objects that compute Grothendieck polynomials.
We introduce a new combinatorial object that naturally recast the pipedream
formula. From this, we obtain the first direct combinatorial formula for the
top degree components of Grothendieck polynomials, also known as the
Castelnuovo-Mumford polynomials. We also prove the inverse fireworks case of a
conjecture of M\'esz\'aros, Setiabrata, and St. Dizier on the support of
Grothendieck polynomials.
