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())

m = 1
ans = 0
prev = 0
while True:
    if n < 10 ** m:
        ans += (n - prev) * m
        break 
    else:
        ans += (10 ** m - 1 - prev) * m
        m += 1
        prev = ans

print(ans) 
