function refuel()
   if turtle.getFuelLevel() == 0 then
      turtle.select(1)
      turtle.refuel(1)
      print("refueling")
   end
end

function plant()
   turtle.select(2)
   turtle.placeDown()
end

function harvest()
   turtle.digDown()
end

function prepare()
   turtle.attackDown()
end

function turnLeft()
   turtle.turnLeft()
   turtle.forward()
   turtle.turnLeft()
end

function turnRight()
   turtle.turnRight()
   turtle.forward()
   turtle.turnRight()
end

function doWork()
   if turtle.getFuelLevel() > 10 then
      for i=1,7 do
         harvest()
         prepare()
         plant()
         turtle.forward()
      end
      harvest()
      prepare()
      plant()
   else
      refuel()
   end
end

function work()
   turtle.turnRight()
   for j=1,3 do
      for i=1,4 do
         doWork()
         turnLeft()
         doWork()
         turnRight()
      end
      turtle.up()
      turtle.turnLeft()
      turtle.forward()
      turtle.turnRight()
   end
end

function main()
   print("Starting")
   refuel()
   turtle.up()
   turtle.up()
   turtle.forward()
   turtle.forward()
   work()
   print("end")
end


main()