

color clear
rect 0,0,400,400

color black
for h = 10 to 150 step 40
for i = 10 to 150 step 40
rect i,h,19,19
next i
next h

for h = 30 to 150 step 40
for i = 30 to 150 step 40
rect i,h,19,19
next i
next h
