#!/opt/perl/bin/perl

# usage: regiontree < maps/regions

my %regions;

sub print_rec {
   my ($reg, $pad) = @_;
   print ((" " x ($pad * 4))."$reg\n");
   for (@{$regions{$reg}->{child}}) {
      print_rec ($_, $pad + 1);
   }
}


my $curreg = '';
while (<STDIN>) {
   if (/^region\s*(\S+)\s*$/) {
      $curreg = $1;
      $regions{$curreg} = {};
   } elsif (/^parent\s*(\S+)\s*$/) {
      $regions{$1} = {} unless exists $regions{$1};
      $regions{$curreg}->{parent} = $1;
      push @{$regions{$1}->{child}}, $curreg;
   }
}

for (sort grep { not $regions{$_}->{parent} } keys %regions) {
   print_rec ($_);
}