for(0..($s=<>)-1){$b=$a=$"x($s+($s>1));$v=$s-$_-1;substr$a,$_,1,X for$_,$v;substr$b,$_,1,Y for$_<$s/2?($_,$v):$s/2;$l[$_]=[$a,$b,$"x$v.Z]}$l[$s-1][2]=$l[0][2]=Z x$s;print@$_,$/for@l