Hey Codeforces,

How is 20B - Equation actually rated 2000? The problem is literally high school algebra: solve Ax^2+bx+c=0. Even accounting for basic edge cases (A=0, infinite roots, precision), by today's standards this is an 800–1000 rated Div.2 A at most. Is this just a broken artifact of early Codeforces rating algorithms getting tricked by high submission fail rates in 2010, or am I missing something? What rating do you think it actually deserves today?