$ans = 1;
#	 $kbin = split(/./,unpack('B*',pack('H*',$k)));
#        for ($i=0; $i<$#kbin; i++)
#        {
#                $ans = $ans * $ans % $N;
#                if (substr($kbin,$i,$1) == 1) { $ans = $ans * $M % $N; }
#        }