An umbrella structure includes a cover, {TAIL ~ a shaft}, a notch, a runner, {HEAD ~ main ribs} and stretchers 
An umbrella structure includes a cover , { TAIL ~ a shaft } , a notch , a runner , { HEAD ~ main ribs } and stretchers
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH