#!/usr/bin/perl
use strict;
use warnings;

my @array=(
    21112340,
    21112341,
    21112342,
    21112343,
    21112344,
    21112345,
    21112346,
    21112347,
    21112348,
    21112349,
    21112350,
    21112351,
  );
my %test;
for(@array)
{ $test{$1}+=2**$2 if($_=~/^(\d{7})(\d)/); }

my @new_array;
for my $val (@array)
{
  my $v=substr($val,0,7);
  if($test{$v} && $test{$v}==(2**10)-1)
  { push(@new_array,$v) if(!@new_array or $new_array[-1]!=$v); }
  else
  { push(@new_array,$val) }
}

print "$_\n" for(@new_array);