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.
n = int(input())

number = 9
p = 9
d = 1
ans = 0

while number < n:
    ans += p * d
    p *= 10
    d += 1
    number += p

ans += (n - (p // 9) + 1) * d
print(ans)