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 f(n,nd):
	if(nd is 0):
		return 0
	return ((n-10**(nd-1))+1)*nd+f((10**(nd-1))-1,nd-1)
n=int(input())
k=n
nd=0
while(k!=0):
	k=k//10
	nd+=1
print(f(n,nd))