#!/usr/bin/perl -w

$lastline = '';
while (<>) {
    my $line = $_;
    if ($line =~ /^\s*$/) {
	if ($lastline =~ /.*:\s*$/) { # empty rule elide two lines
	    $lastline = '';
	    next;
	}
    }
    print $lastline;
    $lastline = $line;
}