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.
s = []

for i in range(10):
    s.append((i+1)*(10**(i+1)-10**i))
    
n = int(input())
ind = 0
    
for i in range(len(s)):
    if 10**(i+1) > n:
        ind = i
        break
        
if ind == 0:
    print(n)
else:
    n -= 10**ind
    print(sum(s[:ind])+(ind+1)*(n+1))