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.
def ii():
  return int(input())
def ss():
  return [x for x in input()]
def si():
  return [int(x) for x in input().split()]
def mi():
  return map(int, input().split())

a = ii()
s = 0
nums = 0

for i in range(1, 100):
  if a >= 10 ** i:
    nums += (10 ** (i - 1) * 9) * i
  else:
    break
nums += (a - (10 ** (i - 1) - 1)) * i
print(nums)