def count_rect(rect_map, line, index, h)
  li = line.index('.')
  return 0 if !li

  count_max = 0
  current_h = index

  while li < 10
    ri = li
    ri += 1 while line[ri + 1] == '.'

    (li..ri).to_a.combination(2).each do |set|
      count = 0
      _li, _ri = set.min, set.max
      while rect_map[current_h][_li.._ri].all?{ |x| x == '.' }
        count += _ri-_li+1
        current_h += 1
        break if h <= current_h
      end
      count_max = count if count_max < count
      current_h = index
    end
    li = ri + 1
    li += 1 while line[li] != '.' && li <= 10
  end

  count_max
end

loop do
  h, w = gets.chomp.split.map(&:to_i)
  break if [h, w].all?(&:zero?)

  star_map = Array.new
  h.times { star_map << gets.chomp.split('') }

  puts star_map.map.with_index{ |l, i| count_rect(star_map, l, i, h) }.max
end