For |x-2|, the value can be 1 0, so the maximum value is1; For |y-x|, the value can be 0 1 2, so the maximum value is 2, that is, the maximum value of a is 3.

X = 1Y = 3。 X = 3Y = 1 The total is 3 = 9P = 2/9.

When a= 1

1.x-2=0 |y-x|= 1, so x = 2 y= 1, 32. Y-x = 0 | x-2 | = 1, so x= 1 and y = 65438.

1/3