The number of {HEAD ~ the first protruding portions} 141 a equals to {TAIL ~ the number} of the through holes 144 
The number of { HEAD ~ the first protruding portions } 141 a equals to { TAIL ~ the number } of the through holes 144
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH