H, W = gets.split.map(&:to_i)
P = H.times.map { gets.chomp.chars }

def f(cx, cy)
  dist = 0

  P.each.with_index(1) do |row, y|
    row.each.with_index(1) do |c, x|
      next if c == '0'
      dy = y - cy
      dx = x - cx

      dist += Math.sqrt(dy ** 2 + dx ** 2)
    end
  end

  dist
end

min_dist = Float::INFINITY

0.upto(W + 1) do |x|
  0.upto(H + 1) do |y|
    next if 1 <= y && y <= H && 1 <= x && x <= W
    next if y == 0 && x == 0
    next if y == 0 && x == W + 1
    next if y == H + 1 && x == 0
    next if y == H + 1 && x == W + 1

    dist = f(x, y)
    if min_dist > dist
      min_dist = dist
    end
  end
end

puts "%.12f" % min_dist