А. !!
Автор задачи: Добролюбов Дмитрий
Первоисточник: тестовые задачи
URL первоисточника: contest.samara.ru
Задачу добавил: Dobriy
Успешно сдано решений: 265
Douyble factorial is a product of odd or even factors from 1 to n, if the n is odd then all factors are odd, else all factors are even.
Input:
First line consist only one integer number n, 0 Output: First line of output consist n!!