Topological Sort

Score: 106.47 (pass)

Grotty \Q\E, grotty fix for reflexives. Room for improvement...

#!perl
$_=join'',<>;s/^(.*) \1$/$1/mg;s/^\Q$y\E\s//mg,print"$y
"while$x=$_,($y)=grep$x!~/ \Q$_\E
/,split;/ /&&die