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.
from math import *
n = int(input())
r = 0
i = 0
l = 10
while l < n:
    r += (i+1)*(l-l//10)
    i += 1
    l *= 10
print(r + (i+1)*(n - l//10 + 1))
