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.
'''input()
numbers = input().lstrip('0')

def factorial(n):
	m = 1
	for i in range(2, n+1):
		m *= i
	return m

factorials = tuple(map(factorial, range(1, 10)))

ans = 1
for i in numbers:
	ans *=  factorials[int(i) - 1]'''

num = input()
ln = len(num)
num = int(num)
ans = 0

gen = (10**x for x in range(1, 10))
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)