#!/usr/bin/perl

$a = $ARGV[0];
place($a-6,0,(1..$a));

sub place
{
  if ($_[0]) {
    for my $c ($_[1]+2..$#_) {
      place($_[0]-1,$c-2,@_[2..$c-1],'#',@_[$c+1..$#_])
	      unless $_[$c] eq '#';
    }
  }
  else {
    print @_[2..$#_],"\n";
  }
}