9-И-3 ex.5

a=int(input())

def dl(a):
    '''a: integer'''
    n = 0
    while a != 0:
        n += 1
        a //= 10
    return n

def fuct(a):
    ans=1
    for i in range(1,a+1):
        ans*=i
    return ans
print(fuct(dl(a)))