advanced room builder

	print("load building material in all slots")
	print("	place turtle at bottom right corner (builds in place)")
    print("first wall?")
    local x=tonumber(read())
    print("second wall?")
    local y=tonumber(read())
    print("height?")
    local z=tonumber(read())
    local count=0
    local slot =1

    function ensureSlot()
    if count==0 then
    slot=slot+1;
    count=turtle.getItemCount(slot)
    if count==0 then exit() end
    turtle.select(slot)
    end
    end

    count=turtle.getItemCount(slot)
    turtle.turnRight();turtle.turnRight();
	local zr=0;
	z=z-1
	zr=z %3
	z=math.floor(z/3)
	if (zr~=0) then z=z+1 end
	local buildUp=true;
	local buildForward=true;
    for k=1,z do
	if(k<z) then buildUp=true;buildForward=true;
	elseif zr==1 then   buildUp=false;buildForward=false;
	elseif zr==2 then   buildUp=false;buildForward=true;
	else 				buildUp=true ;buildForward=true;
	end


    turtle.up()

	for j=1,2 do
            for i=1,x-2 do
					turtle.placeDown()
					count=count-1;ensureSlot()
					if buildUp then
					turtle.placeUp()
                    count=count-1;ensureSlot()
					end
					turtle.back()
					if buildForward then
					turtle.place()
                    count=count-1;ensureSlot()
					end
            end
            turtle.placeDown()
			count=count-1;ensureSlot()
			if buildUp then
				turtle.placeUp()
                count=count-1;ensureSlot()
			end
            turtle.turnLeft()
            turtle.back()
			if buildForward  then
				turtle.place()
               count=count-1;ensureSlot()
			end

            for i=1,y-2 do
					turtle.placeDown()
					count=count-1;ensureSlot()
					if buildUp then
					turtle.placeUp()
                    count=count-1;ensureSlot()
					end
					turtle.back()
					if buildForward then
					turtle.place()
                    count=count-1;ensureSlot()
					end
            end
            turtle.placeDown()
			count=count-1;ensureSlot()
			if buildForward and j==2 then
					turtle.up()
					turtle.placeDown()
                    count=count-1;ensureSlot()
			end
			if buildUp then
				if j==1 then
					turtle.placeUp()
                    count=count-1;ensureSlot()
				else
					turtle.up()
					turtle.placeDown()
                    count=count-1;ensureSlot()
				end
			end

            turtle.turnLeft()
            turtle.back()
			if buildForward and j==1 then
				turtle.place()
               count=count-1;ensureSlot()
			end

    end
    end

	turtle.forward()
	turtle.up()
	for j=1,y do
		for i=1,x-1 do

	        turtle.placeDown()
			count=count-1;ensureSlot()
			   turtle.back()
    	end
			turtle.placeDown()
			count=count-1;ensureSlot()
			if(j%2== 1) then turtle.turnLeft() else turtle.turnRight() end
	        turtle.back()

            if(j%2== 1) then turtle.turnLeft() else turtle.turnRight() end
            --turtle.back()

	end
	if(zr~=0) then z=z-1; end
	z=z*3+zr
	for i=1,z do turtle.down() end