The five main grooves include {TAIL ~ a single first main groove}, {HEAD ~ two second main grooves}, and two third main grooves 
The five main grooves include { TAIL ~ a single first main groove } , { HEAD ~ two second main grooves } , and two third main grooves
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH