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 main():
    n = int(input())

    d = 1
    s = 0
    while True:
        nNumbers = 9 * (10 ** (d - 1))
        if n - nNumbers > 0:
            n -= nNumbers
            s += d * nNumbers
        else:
            s += d * n
            break
        d += 1
    print(s)


if __name__ == "__main__":
    main()
