Potyczki Algorytmiczne 2009

Trial Round£º Rectangles \[ans=\sum_{1\leq i\leq j\leq n}[ij\leq n]=\frac{\lfloor\sqrt{n}\rfloor+\sum_{1\leq i,j\leq n}[ij\leq n]}{2}=\frac{\lfloor\sqr