obsidian

red = 1
delay = 15
lever = "left"
button = "right"

while true do
    turtle.select(red)
    num = turtle.getItemCount(red)
    if num < 3 then
        error("Out of redstone", 0)
    end
    for i=0, 2 do
        turtle.forward()
    end
    for i=0, 2 do
        turtle.place()
        turtle.back()
    end
    rs.setOutput(lever, true)
    sleep(delay)
    rs.setOutput(lever, false)
    rs.setOutput(button, true)
    sleep(1)
    rs.setOutput(button, false)
    for i=0, 2 do
        turtle.forward()
        turtle.dig()
    end
    for i=0, 2 do
        turtle.back()
    end
end