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())
answer = 0
answer = min(9, n) * 1
if n >= 10:
    answer += min(90, n - 9) * 2
for cnt_zero in range(3, 11):
    if n < 10 ** (cnt_zero - 1):
        break
    answer += min(9 * (10 ** (cnt_zero - 1)), n - 10 ** (cnt_zero - 1) + 1) * cnt_zero

print(answer)