func main()
	var pos: []Pos :: #[3]Pos
	for i(0, 2)
		do pos[i] :: (#Pos).init(cui@inputInt(), cui@inputInt())
	end for
	for i(0, 2)
		if(i <> 0)
			var t: Pos :: ##pos[0]
			do pos[0].init(pos[i].x, pos[i].y)
			do pos[i].init(t.x, t.y)
		end if
		if((pos[1].x - pos[0].x) * (pos[2].x - pos[0].x) + (pos[1].y - pos[0].y) * (pos[2].y - pos[0].y) = 0)
			if((pos[1].x - pos[0].x) ^ 2 + (pos[1].y - pos[0].y) ^ 2 = (pos[2].x - pos[0].x) ^ 2 + (pos[2].y - pos[0].y) ^ 2)
				do cui@print("\{pos[2].x + pos[1].x - pos[0].x} \{pos[2].y + pos[1].y - pos[0].y}\n")
				ret
			end if
		end if
	end for
	do cui@print("-1\n")
	
	func swap(a: &Pos, b: &Pos)
		var pos: Pos :: ##a
		do a :: ##b
		do b :: ##pos
	end func
	
	class Pos()
		+var x: int
		+var y: int
		+func init(x: int, y: int): Pos
			do me.x :: x
			do me.y :: y
			ret me
		end func
	end class
end func