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![[asy]unitsize(0.3cm);filldraw((10,0)--(10,2)--(12,2)--(12,0)--cycle,red);filldraw((12,0)--(12,2)--(14,2)--(14,0)--cycle,red);filldraw((14,0)--(14,2)--(16,2)--(16,0)--cycle,red);filldraw((11,2)--(11,4)--(13,4)--(13,2)--cycle,red);filldraw((13,2)--(13,4)--(15,4)--(15,2)--cycle,red);filldraw((12,4)--(12,6)--(14,6)--(14,4)--cycle,red);filldraw((0,0)--(0,2)--(2,2)--(2,0)--cycle,red);filldraw((2,0)--(2,2)--(4,2)--(4,0)--cycle,black);filldraw((4,0)--(4,2)--(6,2)--(6,0)--cycle,red);filldraw((1,2)--(1,4)--(3,4)--(3,2)--cycle,yellow);filldraw((3,2)--(3,4)--(5,4)--(5,2)--cycle,yellow);filldraw((2,4)--(2,6)--(4,6)--(4,4)--cycle,yellow);filldraw((20,0)--(20,2)--(22,2)--(22,0)--cycle,yellow);filldraw((22,0)--(22,2)--(24,2)--(24,0)--cycle,red);filldraw((24,0)--(24,2)--(26,2)--(26,0)--cycle,black);filldraw((21,2)--(21,4)--(23,4)--(23,2)--cycle,black);filldraw((23,2)--(23,4)--(25,4)--(25,2)--cycle,yellow);filldraw((22,4)--(22,6)--(24,6)--(24,4)--cycle,red);filldraw((30,0)--(30,2)--(32,2)--(32,0)--cycle,red);filldraw((32,0)--(32,2)--(34,2)--(34,0)--cycle,red);filldraw((34,0)--(34,2)--(36,2)--(36,0)--cycle,yellow);filldraw((31,2)--(31,4)--(33,4)--(33,2)--cycle,red);filldraw((33,2)--(33,4)--(35,4)--(35,2)--cycle,black);filldraw((32,4)--(32,6)--(34,6)--(34,4)--cycle, yellow);[/asy]](http://latex.artofproblemsolving.com/9/8/5/98546e08178370b7538b64caae3f03906b77a409.png)
