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 solve():
    book_num = int(input())
    cur_digit_min = 1
    cur_digit_max = 9
    cur_digit = 1

    result = 0
    while True:
        if book_num > cur_digit_max:
            result += (cur_digit_max-cur_digit_min+1)*cur_digit
            cur_digit += 1
            cur_digit_min *= 10
            cur_digit_max = cur_digit_max*10+9
        else:
            result += (book_num-cur_digit_min+1)*cur_digit
            break

    print(result)


solve()

		 	   	  		  		 		   		 		 	