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 cal_n(n):
	c=0
	while n > 0:
		n = n//10
# 		print(n)
		c+=1
	return c

n = int(input())
if n<=9:
	print(n)
else:
	sz = cal_n(n)
	# print(sz)
	ans=0
	temp = 9
	for i in range(1,sz+1):
		if i!=sz:
			ans += i*temp
			if i+1!=sz:
				temp = temp*10 + 9
		else:
			ans += (n-temp)*i

	print(ans)