And the answer would be this box over here
and this box over here, nothing else.
This guy has clearly 4 positive nearest neighbors,
so no matter what the 5th one is we stay positive.
Similarly, this guy over here,
when you draw a circle,
has probably these 4 guys as nearest neighbors,
perhaps this one as well, but it is a little further away.
With those 4 ones, it already has 3 pluses,
so whatever the 5th one is it can't overturn, it must be positive.
All of these are negative, even this one over here has just 2 pluses as neighbors
that are positive, and those guys over here are all negative.
Similarly, over here there are possibly 2 pluses
in the 5 nearest neighbors,
but these guys over here are all negative, and this guy is
surrounded by negative examples, so they will just be negative.