#!/usr/bin/perl -l

$a=shift;place($a-6,0,(1..$a));sub place{local$_;$_[0]||return print @_[2..$#_];$_[$_] ne'#'&&place($_[0]-1,$_-2,@_[2..$_-1],'#',@_[$_+1..$#_])for($_[1]+2..$#_)}