Given that

(1) x and y are both integers between 100 and 999, inclusive;

(2) y is the number formed by reversing the digits of x; and

(3) z=|x-y|.

How many distinct values of z are possible?

Given that

(1) x and y are both integers between 100 and 999, inclusive;

(2) y is the number formed by reversing the digits of x; and

(3) z=|x-y|.

How many distinct values of z are possible?