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())
k=1
i=1
m=0
while(n//k!=0):
   if(n>k and n>k*10):
      m+=9*k
   else:
      m+=(n-k+1)*i
      break
   i+=1
   k*=10
print(m)
