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 = 9
m = 1
d = 1
ans = 0
while n % (k * m) != n:
    ans += k * m * d
    m *= 10
    d += 1
if m != 1:
    print(ans + (n % (k * m // 10) * d))
else:
    print(n)