while true do

    turtle.select(16)
    if turtle.compareDown() then
        turtle.turnLeft()
    end
    turtle.select(15)
    if turtle.compareDown() then
        turtle.turnRight()
    end

    turtle.select(14)
    if turtle.compareDown() then
        turtle.turnLeft()
        turtle.select(1)
        i = 1
        while i <= 2 do
            turtle.up()
            i = i + 1
        end
        i = 1
        while i <= 3 do
            turtle.dig()
            turtle.down()
            i = i + 1
        end
        turtle.place()
        turtle.turnRight()
    end

    turtle.select(13)
    if turtle.compareDown() then
        turtle.turnRight()
        turtle.select(1)
        i = 1
        while i <= 2 do
            turtle.up()
            i = i + 1
        end
        i = 1
        while i <= 3 do
            turtle.dig()
            turtle.down()
            i = i + 1
        end
        turtle.place()
        turtle.turnLeft()
    end

    turtle.select(12)
    if turtle.compareDown() then
        if turtle.getFuelLevel() <= 100 then
            turtle.suckUp()
            turtle.refuel(2, turtle.getItemCount())
        end
                turtle.select(1)
        turtle.turnLeft()
        turtle.drop()
        turtle.turnRight()
    end

    turtle.forward()

end