Problem Statement

Takahashi wants to send a letter to Santa Claus. He has an envelope with an $X$-yen (Japanese currency) stamp stuck on it.
To be delivered to Santa Claus, the envelope must have stamps in a total value of at least $Y$ yen.
Takahashi will put some more $10$-yen stamps so that the envelope will have stamps worth at least $Y$ yen in total.
At least how many more $10$-yen stamps does Takahashi need to put on the envelope?

Constraints

• $X$ and $Y$ are integers.
• $1 \\le X,Y \\le 1000$

Input

Input is given from Standard Input in the following format:

$X$ $Y$

Output

Print the answer as an integer.

Sample Input 1

80 94

Sample Output 1

2

• After adding zero $10$-yen stamps to the $80$-yen stamp, the total is $80$ yen, which is less than the required amount of $94$ yen.
• After adding one $10$-yen stamp to the $80$-yen stamp, the total is $90$ yen, which is less than the required amount of $94$ yen.
• After adding two $10$-yen stamps to the $80$-yen stamp, the total is $100$ yen, which is not less than the required amount of $94$ yen.

Sample Input 2

1000 63

Sample Output 2

0

The envelope may already have a stamp with enough value.

Sample Input 3

270 750

Sample Output 3

48