Mine

j=0

function fforward()
  while(turtle.forward()==false) do
    turtle.dig()
  end
end

function fdigUp()
  while(turtle.detectUp()) do
    turtle.digUp()
    sleep(0.4)
  end
end

function placeTorch()
  turtle.turnRight()
  turtle.turnRight()
  turtle.select(2)
  turtle.place()
  turtle.turnRight()
  turtle.turnRight()
  j=0
end

function step()
  fforward()
  fdigUp()
  turtle.select(1)
  turtle.placeDown()
  if(j>12) then
    placeTorch()
  end
  j=j+1
end

write("Laenge ?")
l = tonumber(read())

write("Wiederholungen ?")
wdh = tonumber(read())

for o=1, wdh do

for w=1, l do
  step()
end

turtle.turnRight()

for x=1, 3 do
  step()
end

turtle.turnRight()

for y=1, l do
  step()
end

turtle.turnLeft()

for z=1, l do
  step()
end

turtle.turnLeft()

end