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())

x = 10
res = 0
i = 1
while(n // x > 0):
    res += ((x - x / 10) * i)
    i += 1
    x *= 10

res += (n - int(x / 10) + 1) * i;
print(int(res))