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.
i=int(input())
initial=9
d=1
ans=0
while(i>0):
  if(i<initial):
    ans=ans + i*d
    i=0
  else:
    i=i-initial
    ans=ans + initial*d
  initial=initial*10
  d=d+1
print(ans)