Dogs Playing PokerBarry and Kerrie are discussing their pets during a poker game. Barry tells Kerrie that he has at least one dog at home. When Kerrie asks what breed, he answers cryptically: "If I have a Labrador but not a Staffie, I also have a Collie. I either have both a Collie and a Staffie or neither. If I have a Collie, then I also have a Labrador. " What breed or breeds does Barry have at home?