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 = 0
x = 1
y = 9
z = n
while z > 0:
    z //= 10
    k += 1
    y = 10 * y + 9

y //= 100
x = (9 * 10**(k - 2))
z = k * (n - (y + 1) + 1)
print(int(x + z))
