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 solve(n):
    result = 0
    limit = 10
    digit_num = 1
    while n >= limit:
        result += (limit // 10 * 9) * digit_num
        limit *= 10
        digit_num += 1
    result += (n - limit // 10 + 1) * digit_num
    return result

if __name__ == "__main__":
    n = int(input())
    print(solve(n))
