#!/usr/bin/perl

# http://perlmonks.org/?node_id=1178340

use strict;
use warnings;

while(<DATA>)
  {
  print /^(?!.*(?:-|_|^)\d)/ ? "    matched $_" : "not matched $_";
  }

__DATA__
aa1.2
aa1_bb2
aa1_2
aa1_2bb
1aa
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