# 1)

def f(a,b):
    return 18 * a * b
print(f(1,4))
#Ответ: 2

#2)
summa = 0
for i in range(1,11):
    summa += i
print('The sum is',  summa)
#Ответ: 3

#3)
def is_even(n):
    if n % 2 == 0:
        return (n,'is even')
    else:
        return (n, "is odd")
print(is_even(int('4')))
#Ответ: 3

#4)
def factorial(n):
    if n < 0:
        return None
    if n == 0:
        return 1
    else:
        return n * factorial(n - 1)
print(factorial(int(input())))

#5)
def is_palindrom(s):
    s = s.lower()
    for i in range(len(s)):
        if s[i] != s[len(s) - i - 1]:
            return False
    return True
print(is_palindrom('шалаш'))
#6)
def multiplylist(lst):
    if len(lst) == 0:
        return None
    else:
        result = 1
        for i in range(len(lst)):
            result = result * lst[i]
        return result
print(multiplylist([1,2,3,4,5]))