TorchPlacer

--- initialisation ---

print("Please put coal in slot 1 and torches in others slots")
print("how long?")
L = read()
L = math.floor(tonumber(L)/5)
print("how wide?")
W = read()
W = tonumber(W)
slotbase = 2

--- function ---
function testSlot()
  while turtle.getItemCount(slotbase) == 0 do
        slotbase = slotbase +1
        if slotbase == 17 then slotbase = 2 end
  end

function Job()
  for j = 1, W do
  for i = 1,L do
        if turtle.getItemCount(slotbase) == 0 then testSlot() end
        turtle.forward()
        turtle.forward()
        turtle.forward()
        turtle.forward()
        turtle.forward()
          if turtle.detectDown() == false then
                 turtle.placeDown()
          end
  end
  for i = 1, L do
        turtle.forward()
        turtle.forward()
        turtle.forward()
        turtle.forward()
        turtle.forward()
  end
  end

function Fuel()
    if fuelLvL < 2*L*W+10 then
      turtle.select(1)
      if turtle.refuel() == false then
                     print("Please, put fuel in slot 1")
      else
                     turtle.refuel(5)
                     Fuel()
      end
    else
    Job()
  end

Fuel()