function place()
    if not turtle.placeDown() then
        while true do
            if find("minecraft:cobblestone") then
                turtle.select(find("minecraft:cobblestone"))
                break
            else
                print("need more cobble")
                sleep(5)
            end
    
        end
    end
end

function refuel()
    print(turtle.getFuelLevel())
    if  turtle.getFuelLevel() < 1000 then
        found = find("minecraft:coal")
        if found then
            turtle.select(found)
            turtle.refuel(1)
        end
    end
end

function fram(n)
    for i = 1,n do
        refuel()
        place()
        turtle.forward()

    end
end

function find(name)
    for i = 1,16 do
        sname = turtle.getItemDetail(i)
        if sname then
            sname = sname.name
            if name == sname then
                return i
            end
        end
    end
    return false
end 

function filled()
    for u = 1,4 do
        fram(9)
        turtle.turnRight()
        fram(1)
        turtle.turnRight()
        fram(9)
        turtle.turnLeft()
        fram(1)
        turtle.turnLeft()
    end
        fram(9)
        turtle.turnRight()
        fram(1)
        turtle.turnRight()
        fram(9)
        turtle.turnRight()
end

function skip()
    turtle.up()
end

function hollow()
    fram(9)
    turtle.turnRight()
    fram(9)
    turtle.turnRight()
    fram(9)
    turtle.turnRight()
    fram(9)
    turtle.turnRight()
    turtle.up()
end

filled()
hollow()
skip()
skip()
skip()
filled()
hollow()
skip()
skip()
skip()
filled()
hollow()
skip()
skip()
skip()
filled()
hollow()
skip()
skip()
skip()
filled()
hollow()
skip()
skip()
skip()
filled()
hollow()
skip()
skip()
skip()
filled()
hollow()
skip()
skip()
skip()
filled()
hollow()
skip()
skip()
skip()