What does "af echad lo" mean? For instance, if I say "af echad lo lobesh choolzah" does that mean "nobody is wearing a shirt" or "nobody is not wearing a shirt"?

Question

What does "af echad lo" mean?  For instance, if I say "af echad lo lobesh choolzah" does that mean "nobody is wearing a shirt" or "nobody is not wearing a shirt"?

Answer

it means "nobody is wearing a shirt"
or to be more exact "not even one is wearing a shirt"