Why do you want me to do math?

Spammers have gotten pretty tricky these days. To prevent them from taking over my email box, I wanted to come up with something that their programs wouldn't easily automate. This simple math will help. Spamming robots will have a hard time automating the response to this equation.

I apologize for any inconvenience this may cause you, but I assure you, this math equation that you're answering will help me in the long run.