fcn mdroot(n){
   count:=0; mdr:=n;
   while(mdr > 9){
      m:=mdr; digitsMul:=1;
      while(m){
	 reg md;
	 m,md=m.divr(10);
	 digitsMul *= md;
      }
      mdr = digitsMul;
      count += 1;
   }
   return(count, mdr);
}