These values are processed using {HEAD ~ four sub stages} in {TAIL ~ the MD5 stage} using a number of adders along with fixed nonlinear function processing units and fixed 32 bit shift units 
These values are processed using { HEAD ~ four sub stages } in { TAIL ~ the MD5 stage } using a number of adders along with fixed nonlinear function processing units and fixed 32 bit shift units
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH