my %mapping;
while (<>) {
  my ($key, $value) = /^(.*?)=(.*)$/ or die "Cannot parse $_";
  $mapping{$key}{$_} = 1 for split /, /, $value;
}
for my $word (sort keys %mapping) {
  my @aliases = sort keys %{$mapping{$word}};
  print "$word=", join(", ", @aliases), "\n";
}