stairs down

args = {...}
if #args ~= 2 then
        return print("usage: "..shell.getRunningProgram().." <level to mine down to> <starting level>")
end

n1 = tonumber(args[1])
n2 = tonumber(args[2])

if turtle.getFuelLevel() < (n2-n1*2+1) then
    return print("Not enough fuel!")
end

function dig()
    while turtle.dig() do
        sleep(0.4)
    end
end

function digUp()
    while turtle.digUp() do
        sleep(0.4)
    end
end

turtle.digDown()
dig()
turtle.forward()
for i = n1,n2 do
    digUp()
    dig()
    turtle.digDown()
    turtle.down()
    turtle.digDown()
    dig()
    turtle.forward()
end