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.
import math as m
n = int(input())
i = 1
ans=0
while i <= m.floor(m.log(n,10))+1:
    ans+= i*(min(10**(i)-1,n)-10**(i-1)+1)
    i+=1
    #print(ans)
print(ans)