placeWither()

function placeWither()
    turtle.turnRight()
    turtle.place()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnRight()
    turtle.place()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnRight()
    turtle.place()
    turtle.turnRight()
    turtle.place()
    turtle.turnRight()
    turtle.turnRight()
    turtle.forward()
end

function moveForward(d)
    d = d or 1
    for a = 1, d do
        turtle.forward()
    end
end

turtle.forward()

while true do
    moveForward(4)
    if turtle.refuel(0) then
        turtle.select(1)
        turtle.refuel(1)
        local i = 0
        while i < 10 do
            turtle.select(2)
            placeWither()
            i = i + 1
        end

        turtle.down()
        turtle.down()
        turtle.turnRight()
        turtle.turnRight()
        moveForward(35)
        turtle.up()
        turtle.up()
        turtle.turnRight()
        turtle.turnRight()
        turtle.forward()
        sleep(300)
    end
end