$n=<>;
$x=$y=0;
$u=1;
for(1..$n*$n){
	$$y[$x]=sprintf"%03d",$_;
	if($x+$u==$n||$y+$v==$n||$x+$u<0||$y+$v<0||${$y+$v}[$x+$u]){
		($u,$v)=(-$v,$u);
	}
	$x+=$u;$y+=$v;
}
for(0..$n-1){
	print"@$_\n";
}