($n,$k)=glob<>;
$m=int(($n-1)/$k)+1;
print$m,$/;
for(0..$n-1){
	while($a[$y][$x]){
		$x=($x+1)%$m;
	}
	$a[$y][$x]=1;
	$x=($x+1)%$m;
	$y=($y+1)%$m;
}

for$y(0..$m-1){
	for$x(0..$m-1){
		if($a[$y][$x]){
			print'#';
		}else{
			print'.';
		}
	}
	print$/;
}