For example {TAIL ~ a large cell} of each primary color and black can be placed in {HEAD ~ the four corners} 
For example { TAIL ~ a large cell } of each primary color and black can be placed in { HEAD ~ the four corners }
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD