Formula to calculate if 0

See the following image:

In cell B5 I have =(AND(IF(B2=0,SUM(2+2),0),IF(B3="",SUM(2+2),0))) and it is saying TRUE, instead of calculating and giving me 4. I don't know why.

What I want is, if I enter 0 for Apple in cell B2 and leave cell B3 for Orange blank (must be blank or an error will appear), only then I want cell B5 to calculate 2+2=4. Now, if I enter 0 for Orange in cell B3 and leave cell B2 for Apple blank (must be blank or an error will appear), then I want cell B5 to have a value of 0.