dig

arg = {...}


local xs = arg[1] or 10
local ys = arg[2] or arg[1] or 10

local dir = 0


function sDig()

    while not turtle.forward() do turtle.dig() end
end

function step()

    sDig()
    turtle.digUp()
    turtle.digDown()
end

function turn()

    if dir == 0 then
        turtle.turnRight()
        sDig()
  turtle.digUp()
  turtle.digDown()
        turtle.turnRight()
        dir = 1
    else
        turtle.turnLeft()
        sDig()
  turtle.digUp()
  turtle.digDown()
        turtle.turnLeft()
        dir = 0
    end
end


for x = 1, xs do

    for y = 1, ys do

        step()

    if x == xs then

      if  y == ys then

      else
      turn()

      end

    else
      turn()
    end

  end

end