#!/usr/bin/perl -w

my (%nations_in_class);

foreach $line(<>) {
  my ($nation,$classes_list) = ($line =~ /(\S+)\s+(.*)/);
  my @class_set = split /\s+/,$classes_list;
  foreach my $class(@class_set) {
      push @{$nations_in_class{$class}}, $nation;
  }
}

for my $class (sort keys %nations_in_class) {
  print $class, ' ' x (20-length $class), join (' ', @{$nations_in_class{$class}}), "\n";
}