digger

for i=0, 12 do
    local st, v = turtle.inspectDown()
    if st == nil then
        print("block is air")
        break
    end
    if v.name ~= "appliedenergistics2:sky_stone_block" then
        print(string.format("expect sky stone, got %s", v.name))
        break
    end
    turtle.digDown()
    turtle.down()
    print("fuel=", turtle.getFuelLevel())
end