#!/bin/bash

a=(a b c d e f g h i j k l m n o p q r s t u v w x y z);

for b in ${a[*]}; do

for c in ${a[*]}; do

for d in ${a[*]}; do

for e in ${a[*]}; do

echo -ne "$b$c$d$e.org\r" > /dev/stderr

if ! host $b$c$d$e.org > /dev/null; then

echo $b$c$d$e.org

fi

done

done

done

done