If you want to preserve the sequence in which you got them, just inserting in a hash won't do as the keys will come back in a pseudorandom order. In that case, you need something like this:

#/usr/bin/perl -w
use strict;

my %seen;
my @uniq = grep !$seen{$_}++, <>;

print map "$_\n", @uniq;
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You can also look up counts by changing the last line to something like

print map "$_: $seen{$_}\n", @uniq;
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Makeshifts last the longest.