#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)



int H, W; string G[1010];
//-----------------------------------------------------------------------------------
int dx[8] = { 0,1,1,1,0,-1,-1,-1 };
int dy[8] = { -1,-1,0,1,1,1,0,-1 };
int C[1010][1010];
vector<int> T, cnt;
vector<set<int>> E;
void makeTree() {
    rep(y, 0, H) rep(x, 0, W) C[y][x] = -1;
    int c = 0;
    rep(y, 0, H) rep(x, 0, W) if (C[y][x] < 0) {
        int d;

        if (G[y][x] == '.') T.push_back(0), d = 2;
        else T.push_back(1) , d = 1;

        queue<int> que;
        que.push(y * 1010 + x);
        C[y][x] = c;
        cnt.push_back(1);
        while (!que.empty()) {
            int q = que.front(); que.pop();
            int xx = q % 1010;
            int yy = q / 1010;
            for (int i = 0; i < 8; i += d) {
                int xxx = xx + dx[i];
                int yyy = yy + dy[i];
                if (xxx < 0 || W <= xxx) continue;
                if (yyy < 0 || H <= yyy) continue;
                if (G[y][x] != G[yyy][xxx]) continue;
                if (0 <= C[yyy][xxx]) continue;

                C[yyy][xxx] = c; cnt[c]++;
                que.push(yyy * 1010 + xxx);
            }
        }

        c++;
    }

    E.resize(c);

    rep(y, 0, H) rep(x, 0, W) {
        rep(i, 0, 4) {
            int xx = x + dx[i * 2];
            int yy = y + dy[i * 2];
            if (xx < 0 || W <= xx) continue;
            if (yy < 0 || H <= yy) continue;
            if (C[yy][xx] == C[y][x]) continue;

            int ca = C[y][x];
            int cb = C[yy][xx];

            E[ca].insert(cb);
            E[cb].insert(ca);
        }
    }
}
//-----------------------------------------------------------------------------------
pair<int, int> dfs(int cu, int pa = -1) {
    if (T[cu] == 0) { // ="."
        int a = 0, b = 0;
        for (int to : E[cu]) if (to != pa) {
            auto p = dfs(to, cu);
            a += max(p.second, p.first);
            b += p.second;
        }
        return { a, b };
    } else { // ="x"
        int a = cnt[cu], b = 0;
        for (int to : E[cu]) if (to != pa) {
            auto p = dfs(to, cu);
            a += p.second;
            b += max(p.first, p.second);
        }
        return { a,b };
    }
}
//-----------------------------------------------------------------------------------
int main() {
    cin >> H >> W;
    rep(y, 1, H + 1) cin >> G[y];
    rep(x, 0, W + 2) G[0] += ".";
    rep(y, 1, H + 1) G[y] = "." + G[y] + ".";
    rep(x, 0, W + 2) G[H + 1] += ".";
    W += 2; H += 2;

    makeTree();

    auto p = dfs(0);
    int ans = max(p.first, p.second);
    cout << ans << endl;
}