Hi,
What to add in gate until output = B

 

Home work ?
Sorry the question makes no sense ,

 

XOR gate 74LS86.
CMOS variety is CD4070.
Note that the pinouts are not the same.

 

Home work ?
Sorry the question makes no sense ,

Yes , Home work

 

You are just throwing your homework up asking people to do it for you.

That's not how it works.

YOU need to post YOUR best attempt to work YOUR homework. We will then try to help you see where you are going wrong and guide you a back to a good path. We will NOT do your homework for you.

Also, be aware that you are using very non-standard descriptions and notation. You will probably need to spend some time helping use figure out what you mean in terms that we can understand.