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