$owo = "c:/scripts/owo.txt";

##</code><code>##

open (OWO, "+>$owo") or die $!;

##</code><code>##

@ary = <OWO>;

##</code><code>##

%hsh;

##</code><code>##

undef @hsh{@ary};

##</code><code>##

@list = keys %hsh;

##</code><code>##

print  @list;