Score : $100$ points
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 is given from Standard Input in the following format:
Print the answer as an integer.
The envelope may already have a stamp with enough value.