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.
import sys
input = lambda:sys.stdin.readline()

int_arr = lambda: list(map(int,input().split()))
str_arr = lambda: list(map(str,input().split()))
get_str = lambda: map(str,input().split())
get_int = lambda: map(int,input().split())
get_flo = lambda: map(float,input().split())

mod = 1000000007

def solve():
	tot = 0
	j = 1
	n = int(input())
	for i in range(1,n+1):
		j = len(str(i))
		tot += j
	print(tot)



# for _ in range(int(input())):
solve()
