Vanya got an important task — he should enumerate books in the library and label each book with its number. Each of the *n* books should be assigned with a number from 1 to *n*. Naturally, distinct books should be assigned distinct numbers.

Vanya wants to know how many digits he will have to write down as he labels the books.
The first line contains integer *n* (1 ≤ *n* ≤ 10<sup class="upper-index">9</sup>) — the number of books in the library.
import math
def main():
    a =int(input())
    nn=int(a)
    m = int(0)
    while nn > 0:
        nn =int (nn) / 10
        m = m + int(1)
    nine1 =int( (int(math.pow(10, m-1)) / 10) - 1)
    nine2 = int (0)
    while nine1 > 0:
        nine2 = nine2 + int(nine1)
        nine1 = int(nine1) / 10
    ru=int((a * (m-1)) - nine2)
    print(ru)