use strict;
my %suits;
while (<>) {
        $suits{$1}++ if /(hearts|clubs|spades|diamonds)/;
}
print ($_ . "\n") x $suits{$_} for (keys %suits);
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All criticism above is extremely useful. I'd also like to add that print stringifies its arguments anyway, so "$suit" is useless; it may also be harmful later in the development cycle.