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,r,s,x=int(input()),1,0,1
while x<=n//10:
    x*=10
    s+=9*r
    r+=1
x=n-x+1
s+=r*x
print(s)