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.
books = int(input())
i = 1
res = 0

if books < 10:
    print(books)

else:
    while(i <= 9):
        if books // pow(10, i) == 0:
            i -= 1
            break
    
        else:
            res += 9 * pow(10, i - 1)

        i += 1

    resto = books - pow(10, i)
    res += resto * (i + 1) + (i + 1) 

    print(res)
