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())
ans = 0
ans1 = 0
for i in range(1, 10):
    if n >= 10 ** i:
        ans += 10 ** (i - 1) * 9 * i
        ans1 = 10 ** (i - 1) * 9
    else:
        ans += (n - ans1) * i
        break
print(ans)  