wherein {TAIL ~ a nearest distance} between {HEAD ~ the first dummy metal} and the second dummy metal is more than a nearest distance between the third dummy metal and the fourth dummy metal, and 
wherein { TAIL ~ a nearest distance } between { HEAD ~ the first dummy metal } and the second dummy metal is more than a nearest distance between the third dummy metal and the fourth dummy metal , and
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH