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.
from sys import stdin
import math
n=int(stdin.readline())
ans=0
l=math.floor(math.log10(n)+1)
for i in range(1,11):
    if(i==l):
        ans+=(n-10**(i-1)+1)*i
    elif(i<l):
        ans+=(9 * 10**(i - 1)) * i
    else:
        break
print(ans)
