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?

Input

Input is given from Standard Input in the following format:
X Y

Output

Print the answer as an integer.

Constraints

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

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

见题面 Input 部分

见题面 Output 部分