It depends. K1,p1 is a multiple of 2 so if you're knitting in the round you have to stick to that or you'll be off at the join. In this case it needs to be an even number.
If you are knitting flat you can have one extra stitch (odd number) if you want it to end in a k so it'll match the other side. So..it depends on what you're doing. As an example you'd have k1, p1, k1, p1, k1 .. see?