In a big directory, it's easy to miss that a malformed filename has slipped in. Were this my code, I'd be more defensive about

  $pic =~ s/^(\d+).*/$1/;
  $h++;
  $uniquelist{$pic}++;
  next if ($currentlist{$pic});
  $deletelist{$pic}++;
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and would test whether the regexp actually matched before doing the bookkeeping.