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