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.
def f(n, l):
    s = 0
    for i in range(1, l + 1):
        s += (i * (10 ** (i - 1)))
    return 9 * s

n, k = int(input()), 1
while n > (10 ** k):
    k += 1
print((n - (10 ** (k - 1)) + 1) * len(str(n)) + f((10 ** (k - 1)) - 1, len(str(n)) - 1))