While the minimum number of headphones one should own is three, the correct number is n+1, where n is the number of headphones currently owned.
Ngenkathi inani eliphansi le-amabhayisikili elilodwaokufanele ibe ngeyakhe isithathu, inombolo eyiyo ngu-n+1, kuphininombolo ye-amabhayisikiliephethwe njengamanje.