I agree your original question is wrong, if you wanted output like that, but here's how I did it: (you're lucky I was bored this morning...) 
use strict;

my %hh;

#read in...
while (<DATA>) {
  my ($k, $v) = split /\s*,\s*/;
  chomp $v;
  $hh{$k}{$v}++;
}

#now to print out...
foreach my $k (sort {$a cmp $b} keys %hh) {
  my $tlist = '';
  my $tally = 0;
  foreach my $v (sort {$a cmp $b} keys %{$hh{$k}}) {
    $tally += $hh{$k}{$v};
    $tlist .= "$v, ";
  }
  chop $tlist; chop $tlist; #remove trailing ', '
  print "$tally\t$k\t$tlist\n";
}

__DATA__
abcd, GB
abcd, UK
abcd, US
addd, US

[download]
(hopefully there aren't any typos. I wrote/tested on another machine and typed in by hand...)

Update: fixed a typo in code "== split" should be "= split";

In reply to Re^3: Dear Monks by raybies
in thread Dear Monks by sivaraman

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