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())

res=0
lower=1
upper=9
digit=1

while n>=lower:
    if n<=upper:
        res+=digit*(upper-lower+1)
    else:
        res+=digit*(n-lower+1)
    lower*=10
    upper=(upper+1)*10-1

print(res)