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:
    s = n
else:
    s = 9
    n -= 9
    k = 2
    while n // 10**k > 0:
        s += 10**k * k
        n -= 10**k
        k += 1
    s += n * k
print(s)