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())
st10 = 1
kol=1
while st10 * 10 <= n:
    st10 *= 10
    kol+=1
s=0
while n>9:
    s += (n-st10+1)*kol
    kol-=10
    n =st10-1
    st10//=10
print(s+n)
