How do I tell my teacher the fluorine cation doesn't exist?

From reddit

See, it's funny because the teacher gave the student an F+ on his or her (possibly AI-generated) book report, but the student is claiming not to know that the F+ is meant to be a grade and not a chemical notation for a fluorine atom that has lost an electron. 

Fluorine atoms, being the most electronegative atoms on the planet, are incredibly unlikely to lose an electron rather than to gain an electron.

See, it's funny because of periodic trends!