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.
num = int(input())
n = len(str(num))
lim = [0,0,9,99,999,9999,99999,999999,9999999,99999999,999999999,9999999999]
acum = 0
while num > 0:
    dif = num - lim[n]
    acum += (dif * n)
    num = lim[n]
    n -= 1
print(acum)
