import itertools
surprize =[]
x = int(input())
while x > 1:
    x -= 1
    surprize.append(x)
print (len(list(itertools.permutations (surprize))))

# n = (n - 1) * ((n - 1) + (n - 2))
surprise = []


def f():
    number = int(input())
    number = (number - 1) * ((number - 1) + (number - 2))
    surprise.append(number)


f()
print(surprise[0]//3)

Edited by author 23.08.2020 08:05

Edited by author 04.09.2020 14:21

Edited by author 04.09.2020 14:21

# wrong answer 11
def F(n):
    if n<2:
        return 1
    return n*F(n-1)
n = int(input())
print (int((F(n)+1)//2.718281828459045))

Try this formula f(n) = (n-1)*(f(n-1)+f(n-2)) ;)

Edited by author 27.08.2020 12:50

Edited by author 27.08.2020 12:50