Aliens have come to attack the earth. They give you a five hundred by five hundred matrix and tell you that you have fifteen minutes to invert it by hand, exactly, or they'll destroy your planet. Everyone has given up against the ayy lmao military might, you're our last hope. The matrix isn't sparse or triangular, and it has quite a few irrational entries. The aliens offhandedly mention that the matrix is unitary.
What do you do anon? Can you save the earth from total annihilation?