#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <functional>
#define repeat(i,n) for (int i = 0; (i) < (n); ++(i))
template <typename T> bool setmax(T & l, T const & r) { if (not (l < r)) return false; l = r; return true; }
using namespace std;
struct point_t { int y, x; };
const int dy[] = { -1, 1, 0, 0,  -1, 1, -1, 1 };
const int dx[] = { 0, 0, -1, 1,  -1, -1, 1, 1 };
int main() {
    int h, w; cin >> h >> w;
    vector<vector<bool> > is_x(h, vector<bool>(w));
    repeat (y,h) repeat (x,w) {
        char c; cin >> c;
        is_x[y][x] = c == 'x';
    }
    auto is_on_field = [&](int y, int x) {
        return 0 <= y and y < h and 0 <= x and x < w;
    };
    vector<vector<point_t> > rings;
    vector<vector<int> > rev(h, vector<int>(w, -1));
    function<void (int, int)> make_ring = [&](int y, int x) {
        if (not is_on_field(y, x)) return;
        if (not is_x[y][x]) return;
        if (rev[y][x] != -1) return;
        rings.back().push_back((point_t) { y, x });
        rev[y][x] = rings.size() - 1;
        repeat (i,8) make_ring(y + dy[i], x + dx[i]);
    };
    repeat (y,h) repeat (x,w) if (is_x[y][x] and rev[y][x] == -1) {
        rings.emplace_back();
        make_ring(y, x);
    }
    int n = rings.size();
    rings.emplace_back();
    vector<set<int> > is_in(n + 1);
    vector<vector<bool> > used(h, vector<bool>(w));
    function<void (int, int, int)> analyze_inclusion = [&](int y, int x, int r) {
        if (not is_on_field(y, x)) return;
        if (used[y][x]) return;
        if (rev[y][x] != -1 and rev[y][x] != r) {
            is_in[r].insert(rev[y][x]);
            return;
        }
        used[y][x] = true;
        repeat (i,4) analyze_inclusion(y + dy[i], x + dx[i], r);
    };
    repeat (y,h) {
        analyze_inclusion(y,   0, n);
        analyze_inclusion(y, w-1, n);
    }
    repeat (x,w) {
        analyze_inclusion(  0, x, n);
        analyze_inclusion(h-1, x, n);
    }
    repeat (y,h) repeat (x,w) if (rev[y][x] != -1 and not used[y][x]) {
        int r = rev[y][x];
        for (point_t p : rings[r]) {
            analyze_inclusion(p.y, p.x, r);
        }
    }
    vector<vector<int> > memo(2, vector<int>(n + 1));
    function<void (int)> calculate_score = [&](int r) {
        for (int s : is_in[r]) calculate_score(s);
        memo[1][r] += rings[r].size(); // use r
        for (int s : is_in[r]) memo[1][r] += memo[0][s];
        for (int s : is_in[r]) memo[0][r] += memo[1][s]; // don't use r
        setmax(memo[1][r], memo[0][r]);
    };
    calculate_score(n);
    cout << memo[1][n]<< endl;
    return 0;
}