use warnings;
use strict;

my @data = qw(
    21112340    21112341    21112342    21112343
    21112344    21112345    21112346    21112347
    21112348    21112349    21112350    21112351
    512340    512341    512342    512343
    512344    512345    512346    512347
    512348    512349    512350    512351
);

my %test;
my @new;

for my $item (@data) {
    next if $item !~ /^\d{2,}$/;
    my $suffix = chop($item);
    $test{$item}{$suffix}++;
}

for my $base (keys %test) {
    if (scalar(keys %{$test{$base}}) == 10) {
        push @new, $base;
    }
    else {
        push @new, $base.$_ for keys %{$test{$base}};
    }
}

print "$_\n" for sort @new;