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())
prev_step=0
cur_step=9
_sum=0
count=1
while n>cur_step:
    _sum+=count*(cur_step-prev_step)
    prev_step=cur_step
    cur_step=cur_step*10+9
    count+=1
_sum+=count*(n-prev_step)
print(_sum)