Alternatively, the chewing gum may contain {TAIL ~ combinations} of {HEAD ~ sugar} and sugarless sweeteners 
Alternatively , the chewing gum may contain { TAIL ~ combinations } of { HEAD ~ sugar } and sugarless sweeteners
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH