Mystery pattern#1052
One morning, Rabbit went to check his carrot field. He was unpleasantly surprised to discover that part of the carrot bushes had been crushed to the ground by an unknown force.
After thoroughly inspecting the field, Rabbit noticed that all the trampled carrots formed a pattern based on an equilateral triangle with side . In the plane of this triangle, there is a point . The projections of this point onto the sides of the triangle divide each side into two parts. On each side and its parts, semicircles are constructed with these parts as diameters, which together form three drop-shaped figures.
Rabbit became curious about the area of plantations damaged by the unknown force. Unfortunately, this problem was too difficult for him. Your task is to help Rabbit and answer his question.
The only line contains an integer (0 < L \leq 10^6).
Output a single number: the total area of the damaged planting in Rabbit's field, rounded to exactly decimal places.
Пример 1