function start()
  while turtle.detect() do
    turtle.turnLeft()
  end
end
start()
a = 0
function detect()
  if a < 6 then
    while turtle.detect() do
    print("Avance")
      turtle.dig()
      turtle.forward()
      a = a + 1
    end
  end
  if a >= 5 then
    print("Recul")
    turtle.back()
    turtle.back()
    turtle.back()
    turtle.back()
    turtle.back()
    vider()

  end
end
function refuel()
  if turtle.getFuelLevel() < 11 then
    turtle.select(1)
    turtle.refuel(1)
  end
end
function vider()
  turtle.turnLeft()
  turtle.tranferTo(2)
       a = 0
end
while true do
  detect()
  refuel()
end