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())

m, digit = n, 0
while(m != 0):
    m //= 10
    digit += 1

sum_of_digits = 0
for i in range(digit-1):
    sum_of_digits += ((i+1) * (9 * (10**i)))   

sum_of_digits += ((n - (10**(digit-1)) + 1) * digit)

print(sum_of_digits)