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.
num = input()
ln = len(num)
num = int(num)
ans = 0
 
gen = (10**x for x in range(1, 11))
for i in gen:
	if num >= i:
		ans += (9 * i//10) * (len(str(i)) - 1)
	else:
		ans += (num - i//10 + 1) * (len(str(i)) - 1)
		break
print(ans)