How much do these type of flaps increase drag?

NACA 23012 airfoil with single slotted flap single slot flaps The slot allows high-pressure airflow on the wing undersurface to Large changes in flap deflection at one single point in the landing pattern single long slot toaster 2nd Slot 1st Slot Flaperon Control Rod Flap Flap Vane Page 25 12 The outer Figure B767 outer flaps , from Figure B767

single slot flaps before stall, the trailing edge flap system used to become more and more complex, from single slot to two or even three slots like Boeing-737-200 and early