local base_area = 20 + 8 * zig_depth()
  return 2 * base_area + crawl.random2(base_area)

  local base_area = 5 + 2 * zig_depth()
  return 4 * base_area + crawl.random2(base_area)

  local asqrt = math.sqrt(area)
  local b = crawl.random_range(1 + asqrt / 2, asqrt + 1)

  local function rectangle_eccentricity()
  -- exc is the excentrity for the two rectangle, it grows with depth as
  -- 0, 0-1, 1, 1-2, 2, ...
    local exc = math.floor((zig().depth-1) / 2)
    if ((zig().depth-1) % 2) ~= 0 and crawl.coinflip() then
      exc = exc + 1
    end
    return exc
  end
  local exc = rectangle_eccentricity()
  local b = math.floor(math.sqrt(area+12*exc*exc)) - 4*exc