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.
#encoding: utf-8
n = int(input())

digits_number = 0
power_10 = 1

while power_10 <= n:
    digits_number += n - (power_10 - 1)
    power_10 *= 10

print(digits_number)
 	 	   					   			 	   	 	