x=1 ; m=1 ; n=0 ; while true ; do h=`cat /tmp/prime.txt | tr -d ' \t\r\n' | rev | cut -c $x | sed -e 's/A/10/' -e 's/B/11/' -e 's/C/12/' -e 's/D/13/' -e 's/E/14/' -e 's/F/15/'` ; if [ "$h" == "" ] ; then break ; fi ; n=`echo "$n + ($h * $m)" | bc` ; m=`echo "$m * 16" | bc` ; x=`echo "$x + 1" | bc` ; done ; n=`echo "$n" | tr -d ' \t\r\n' | sed -e 's/[^0-9]//g'` ; echo "$n"

Edit: Random self plug – http://fedoraproject.org/wiki/Fedora_ARM_Installer