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.
n=int(input())
c=0
t=9
r=0
k=0
i=10
if(n<10):
    c=n
else:
    if(n>10):
        while(i<=n):
           r=r+2
           i=i+1
           c=t+r
print(c)
    