a fifth P channel MOS transistor connected between {TAIL ~ the other conductive terminal} of {HEAD ~ each} of said third and fourth P channel MOS transistors and the power supply potential 
a fifth P channel MOS transistor connected between { TAIL ~ the other conductive terminal } of { HEAD ~ each } of said third and fourth P channel MOS transistors and the power supply potential
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH