function fuel()
        if turtle.getFuelLevel() < 10 then
                turtle.select(16)
                turtle.refuel(1)
                turtle.select(1)
        end
end
function detectdown()
        turtle.select(15)
        while turtle.compareDown() do
                fuel()
                turtle.digDown()
                turtle.down()
        end
end
function cut()
        fuel()
        turtle.dig()
        turtle.turnRight()
        turtle.dig()
        turtle.turnLeft()
end
fuel()
turtle.dig()
turtle.forward()
turtle.select(15)
while turtle.compareUp() do
        cut()
        fuel()
        turtle.digUp()
        turtle.up()
end
cut()
fuel()
turtle.forward()
turtle.turnRight()
turtle.dig()
turtle.forward()
fuel()
detectdown()