The input consists of a single line containing eight integers $x_1, y_1, x_2, y_2, x_3, y_3, x_4, y_4$: the coordinates of four points ($-1000 \le x_i, y_i \le 1000$). The points $(x_1, y_1)$, $(x_2, y_2)$, $(x_3, y_3)$, $(x_4, y_4)$ are the vertices of a rectangle with a positive area, listed in counterclockwise order.