Can't you just do:

# add the $cnn to an array to keep order
push @good, $cnn if $lines{$cnn} ne '1';
# add a key to a hash so you don't have to
# loop through the array each time
$lines{$cnn} = 1;
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Then you don't have any dupes, you just have the cc numbers.
I am 100% what you asking because it looks like you have much more going on then was presented. If I am way off please help clue me in.