a=gets.split.each_slice(2).map{|i,j|Complex(i.to_i,j.to_i)}
e=a.find{|i|b,c=a-[i];(i-b).abs2==(d=(i-c).abs2)&&d*2==(b-c).abs2}
t,u=a-[e]
puts e ?(t+u-e).rect*" ":-1