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())
a = [9*10**(i-1) for i in range(13)]
a[0] = 0
count =0
for i in range(1,13):
    if n-a[i] >= 0:
        count += a[i] *i
        n = n- a[i]
    else:
        count += n*i
        break
print(count)