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())
tmp = n
if n < 10:
    print(n)
else:
    s = 0
    k = 1
    p = 10
    while n > 0:
        s += k*(p-int(p//10))
        n -= (p-int(p//10))
        k += 1
        p *=10
        if n < p*k:
            s += k*n
            break
    print(s+1 if tmp % 10 == 0 else s)