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())
k = 1
cnt = 0
x = 9


while True:
    if n > x:
        cnt += x * k
        x += x * 10
        k += 1
    else:
        cnt += (x - (x - (n - (x - 9) // 10))) * k
        break


print(cnt)
