{TAIL ~ a gate electrode} of said {HEAD ~ fourth N channel MOS transistor receives} said input signal; and 
{ TAIL ~ a gate electrode } of said { HEAD ~ fourth N channel MOS transistor receives } said input signal ; and
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH