simple stair

for x=1, 20 do
    while turtle.detect() == true do
        turtle.dig()
        sleep(0.5)
    end
    turtle.forward()
    while turtle.detectUp() == true do
        turtle.digUp()
        sleep(0.5)
    end
    turtle.up()
    while turtle.detectUp() == true do
        turtle.digUp()
        sleep(0.5)
    end
end