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.
a=0
def count_digits(a):
    count=0
    while(a>0):
        count=count+1
        a=int(a/10)
    return count
n=int(input())
i=n
counter=0
while(i>0):
    p=count_digits(i)
    counter=counter+p
    i=i-1

print(counter)
     
