Paparazzi Gennady

The young but promising paparazzi Gennady wants to finally become famous. To do this, he wants to take a picture of a new super star during her walk in the mountains. It is known that the star's path in the mountains consists of $N$ sections. For each valid $i$, the $i$-th section is a vertical half-open interval with coordinates $x = i$ and $y \in [0, h_i)$. For each valid $i$ and $j$, our