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())

if n <= 10:
    n = n + 1 if n == 10 else n
    print(n)
    exit(1)

it = 1
amount = 9
while n > 10**it:
    amount += (n - 9) * (it + 1)
    it += 1

if n == 10**it:
    amount += it - 1

print(amount)