local wlk = { ... }
local totalMoved = 0
local length, width = tonumber(wlk[1]), tonumber(wlk[2])

if #wlk ~= 2 or type(length) ~= "number" or type(width) ~= "number" then --checking user'sInput
  print( "use the program properly!" )
  return
end

local function walkLength() --move forward for (length) times
  for i = 2, length do
    turtle.forward()
    totalMoved = totalMoved + 1
  end
end

face = 0

local function altTurn() --alternating turn (left, left),(right, right)
  if face < 2 then
    face = face+1
    turtle.turnLeft()
  elseif face == 2 then
    face = face+1
    turtle.turnRight()
  else
    face = 0
    turtle.turnRight()
  end
end

local cWidth = 0
turtle.turnRight()
while width ~= cWidth do
  print('Percent done: '..math.floor(totalMoved / (length * width) * 100)..'%')
  walkLength()
  cWidth = cWidth+1
  if width ~= cWidth then -- rechecking
    altTurn()
    turtle.forward()
    altTurn()
  end
end