#!/usr/bin/perl
while (<>) {
  $last = $this;
  $this = $next;
  $next = $_;
  $lastblank = ($last =~ (/^\s*$/));
  $thisblank = ($this =~ (/^\s*$/));
  $nextblank = ($next =~ (/^\s*$/));

  print $this unless (! $lastblank) && ($thisblank) && (! $nextblank);
}
print $next unless ($nextblank) && (! $thisblank);