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
n = int(input())
digits = 0
a = int(math.log10(n)) + 1
for x in range(1, a):
    digits += 10 ** (x - 1) * 9 * x
digits += (n - 10 ** (a - 1) + 1) * a
print(digits)