task10

def convert(num):
    units = ("zero", "one ", "two ", "three ", "four ","five ", "six ", "seven ","eight ", "nine ", "ten ", "eleven ", "twelve ", "thirteen ", "fourteen ", "fifteen ","sixteen ", "seventeen ", "eighteen ", "nineteen ")
    tens =("", "", "twenty ", "thirty ", "forty ", "fifty ","sixty ","seventy ","eighty ","ninety ")

    if num < 0:
        return "minus "+convert(-num)

    if num<20:
        return  units[num]

    if num<100:

        return  tens[num // 10]  +units[int(num % 10)]

    if num<1000:
        return units[num // 100]  +"hundred " +convert(int(num % 100))


print(convert(999))

'''numbers   number as words
0           Zero
9           Nine
10          Ten
12          Twelve
19          Nineteen
25          Twenty five
98          Ninety eight
98          Ninety eight
273         Two hundred and seventy three
400         Four hundred
501         Five hundred and one
617         Six hundred and seventeen
711         Seven hundred and eleven