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

def proB(n):
    k=int(math.log10(n)+1)
    bor=10**(k-1)
    ans=(n-bor+1)*k
    k-=1
    while(k!=0):
        ans+=int( '9'*k )*k
        k-=1
    return ans
    
n=int(input())
print(proB(n))