406995: GYM102672 C Spell

Maleficent got upset when she could not cancel the spell cast upon Aurora because it's infinite and unbreakable. Luckily for us it's not such a big problem because in our version of the story all spells are mathematically described and can be cancelled much easier.

The spell is determined by two positive integer numbers $$$a$$$ and $$$b$$$. The process of cancelling the spell goes as follows:

1. Multiply numbers from $$$a$$$ to $$$b$$$ inclusive
2. Count the sum of digits of the result
3. If the sum of digits isn't less then $$$10$$$, go to step $$$2$$$

To finish the cancellation rite, you need to say the resulting number. Please, help Maleficent to find it.

The first line contains number $$$a$$$, the second  — number $$$b$$$ ($$$1 \le a \le b < 10^{100\,000}$$$). Both numbers have no leading zeros.

Output the resulting number.

1
5

3

6
8

3