secret language hackerrank.com
bash and friends (168 167 chars)

T=ANBYCODUEPFXGQHVIRJZKSLWMT
while read x&amp;&amp;[ "$x" != "DONE" ]
do
[ "$x" \&gt; "E" ]
for((z=1+$?*58;z;z--))do
x=$(tr a-zA-Z `tr A-Z a-z&lt;&lt;&lt;$T`$T&lt;&lt;&lt;$x)
done
echo ${x:6}
done


The magic number isn't so magic: it's obtained by solving a set of simultaneous modular identities obtained from the cycle structure of the permutation.