7 day set? Or maybe a few spare ones 
n+1 is the correct answer I believe
Wife: "What? How many razors does one man need? How many do you have now?"
I'm thinking 366, to cover you for leap years. Any more would be excessive, IMO.
What razor are you bidding on?
In my excitement to be bidding on an old razor on eBay, I told my wife about it.
I love my wife dearly and like to share things with her, especially good or exciting things. I realize now, though, that I should have kept my peace unless and until I win the bidding contest (which may not happen).
Wife: "How much?"
Me: "Uh, about $160 so far..."
Wife: "What? How many razors does one man need? How many do you have now?"
Me: "Uh, three that I use..."
Fortunately, my wife is very tolerant of my excesses. She told me to continue bidding, as long as I don't go crazy, and as long as I trade or sell a razor before getting yet another one...![]()