def pp(c)
    c.each do |l|
        puts l
    end
    puts
end
$dx = [0,1,0,-1]
$dy = [1,0,-1,0]
$m = Array.new
$mm = Array.new
def fill(c,i,j,ch,h,w)
    q = [[i,j]]
    while q.size > 0
        sy, sx = q.shift
        c[sy][sx] = ch
        $m.push([sy,sx]) if ch == "a"
        $mm.push([sy,sx]) if ch == "b"
        for i in 0..3
            cy = sy + $dy[i]
            cx = sx + $dx[i]
            if cy.between?(0,h-1) && cx.between?(0,w-1) && c[cy][cx]=="."
                q.push([cy,cx])
            end
        end
    end
end

w, h = gets.split.map(&:to_i)
c = h.times.map{gets.chomp}
bl = false
c.each_with_index do |line,i|
    line.each_char.with_index do |cc,j|
        next unless cc == "."
        fill(c,i,j,"a",h,w)
        bl = true
        break
    end
    break if bl
end
bl = false
c.each_with_index do |line,i|
    line.each_char.with_index do |cc,j|
        next unless cc == "."
        fill(c,i,j,"b",h,w)
        bl = true
        break
    end
    break if bl
end
#pp c
ret = Float::INFINITY
$m.each do |p|
    $mm.each do |pp|
        t = (p[0] - pp[0]).abs + (p[1] - pp[1]).abs - 1
        ret = t if t < ret
    end
end
p ret