#line 2 "cpplib/util/template.hpp"
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx")
#include<bits/stdc++.h>
using namespace std;
struct __INIT__{__INIT__(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}}__INIT__;
typedef long long lint;
#define INF (1LL<<60)
#define IINF (1<<30)
#define EPS (1e-10)
#define endl ('\n')
typedef vector<lint> vec;
typedef vector<vector<lint>> mat;
typedef vector<vector<vector<lint>>> mat3;
typedef vector<string> svec;
typedef vector<vector<string>> smat;
template<typename T>inline void numout(T t){bool f=0;for(auto i:t){cout<<(f?" ":"")<<i<INF/2?i:"INF";f=1;}cout<<endl;}
template<typename T>inline void numout2(T t){for(auto i:t)numout(i);}
template<typename T>inline void output(T t){bool f=0;for(auto i:t){cout<<(f?" ":"")<<i;f=1;}cout<<endl;}
template<typename T>inline void output2(T t){for(auto i:t)output(i);}
template<typename T>inline void _output(T t){bool f=0;for(lint i=0;i<t.size();i++){cout<<f?"":" "<<t[i];f=1;}cout<<endl;}
template<typename T>inline void _output2(T t){for(lint i=0;i<t.size();i++)output(t[i]);}
#define rep(i,...) for(auto i:range(__VA_ARGS__)) 
#define rrep(i,...) for(auto i:reversed(range(__VA_ARGS__)))
#define repi(i,a,b) for(lint i=lint(a);i<(lint)(b);++i)
#define rrepi(i,a,b) for(lint i=lint(b)-1;i>=lint(a);--i)
#define irep(i) for(lint i=0;;++i)
inline vector<long long> range(long long n){if(n<=0)return vector<long long>();vector<long long>v(n);iota(v.begin(),v.end(),0LL);return v;}
inline vector<long long> range(long long a,long long b){if(b<=a)return vector<long long>();vector<long long>v(b-a);iota(v.begin(),v.end(),a);return v;}
inline vector<long long> range(long long a,long long b,long long c){if((b-a+c-1)/c<=0)return vector<long long>();vector<long long>v((b-a+c-1)/c);for(int i=0;i<(int)v.size();++i)v[i]=i?v[i-1]+c:a;return v;}
template<typename T>inline T reversed(T v){reverse(v.begin(),v.end());return v;}
#define all(n) begin(n),end(n)
template<typename T,typename E>bool chmin(T& s,const E& t){bool res=s>t;s=min<T>(s,t);return res;}
template<typename T,typename E>bool chmax(T& s,const E& t){bool res=s<t;s=max<T>(s,t);return res;}
const vector<lint> dx={1,0,-1,0,1,1,-1,-1};
const vector<lint> dy={0,1,0,-1,1,-1,1,-1};
#define SUM(v) accumulate(all(v),0LL)
template<typename T,typename ...Args>auto make_vector(T x,int arg,Args ...args){if constexpr(sizeof...(args)==0)return vector<T>(arg,x);else return vector(arg,make_vector<T>(x,args...));}
#line 5 "cpplib/graph_tree/graph_template.hpp"
/**
 * @brief グラフテンプレート
 */

using graph=std::vector<std::vector<int>>;
template<typename T>
using graph_w=std::vector<std::vector<std::pair<int,T>>>;

graph load_graph(int n,int m){
    graph g(n);
    for(int i=0;i<m;++i){
        int s,t;
        std::cin>>s>>t;
        --s;--t;
        g[s].push_back(t);
        g[t].push_back(s);
    }
    return g;
}
graph load_digraph(int n,int m){
    graph g(n);
    for(int i=0;i<m;++i){
        int s,t;
        std::cin>>s>>t;
        --s;--t;
        g[s].push_back(t);
    }
    return g;
}
graph load_graph0(int n,int m){
    graph g(n);
    for(int i=0;i<m;++i){
        int s,t;
        std::cin>>s>>t;
        g[s].push_back(t);
        g[t].push_back(s);
    }
    return g;
}
graph load_digraph0(int n,int m){
    graph g(n);
    for(int i=0;i<m;++i){
        int s,t;
        std::cin>>s>>t;
        g[s].push_back(t);
    }
    return g;
}
graph load_tree(int n){
    graph g(n);
    for(int i=0;i<n-1;++i){
        int s,t;
        std::cin>>s>>t;
        --s;--t;
        g[s].push_back(t);
        g[t].push_back(s);
    }
    return g;
}
graph load_tree0(int n){
    graph g(n);
    for(int i=0;i<n-1;++i){
        int s,t;
        std::cin>>s>>t;
        g[s].push_back(t);
        g[t].push_back(s);
    }
    return g;
}
graph load_treep(int n){
    graph g(n);
    for(int i=0;i<n-1;++i){
        int t;
        std::cin>>t;
        g[i+1].push_back(t);
        g[t].push_back(i+1);
    }
    return g;
}

template<typename T>
graph_w<T> load_graph_weight(int n,int m){
    graph_w<T> g(n);
    for(int i=0;i<m;++i){
        int s,t;
        T u;
        std::cin>>s>>t>>u;
        --s;--t;
        g[s].emplace_back(t,u);
        g[t].emplace_back(s,u);
    }
    return g;
}
template<typename T>
graph_w<T> load_digraph_weight(int n,int m){
    graph_w<T> g(n);
    for(int i=0;i<m;++i){
        int s,t;
        T u;
        std::cin>>s>>t>>u;
        --s;--t;
        g[s].emplace_back(t,u);
    }
    return g;
}
template<typename T>
graph_w<T> load_graph0_weight(int n,int m){
    graph_w<T> g(n);
    for(int i=0;i<m;++i){
        int s,t;
        T u;
        std::cin>>s>>t>>u;
        g[s].emplace_back(t,u);
        g[t].emplace_back(s,u);
    }
    return g;
}
template<typename T>
graph_w<T> load_digraph0_weight(int n,int m){
    graph_w<T> g(n);
    for(int i=0;i<m;++i){
        int s,t;
        T u;
        std::cin>>s>>t>>u;
        g[s].emplace_back(t,u);
    }
    return g;
}
template<typename T>
graph_w<T> load_tree_weight(int n){
    graph_w<T> g(n);
    for(int i=0;i<n-1;++i){
        int s,t;
        T u;
        std::cin>>s>>t>>u;
        --s;--t;
        g[s].emplace_back(t,u);
        g[t].emplace_back(s,u);
    }
    return g;
}
template<typename T>
graph_w<T> load_tree0_weight(int n){
    graph_w<T> g(n);
    for(int i=0;i<n-1;++i){
        int s,t;
        T u;
        std::cin>>s>>t>>u;
        g[s].emplace_back(t,u);
        g[t].emplace_back(s,u);
    }
    return g;
}
template<typename T>
graph_w<T> load_treep_weight(int n){
    graph_w<T> g(n);
    for(int i=0;i<n-1;++i){
        int t;
        T u;
        std::cin>>t>>u;
        g[i+1].emplace_back(t,u);
        g[t].emplace_back(i+1,u);
    }
    return g;
}
#line 2 "code.cpp"

#include <algorithm>
#include <cassert>
#include <limits>
#include <queue>
#include <vector>

namespace atcoder {

template <class Cap, class Cost> struct mcf_graph {
  public:
    mcf_graph() {}
    mcf_graph(int n) : _n(n), g(n) {}

    int add_edge(int from, int to, Cap cap, Cost cost) {
        assert(0 <= from && from < _n);
        assert(0 <= to && to < _n);
        int m = int(pos.size());
        pos.push_back({from, int(g[from].size())});
        g[from].push_back(_edge{to, int(g[to].size()), cap, cost});
        g[to].push_back(_edge{from, int(g[from].size()) - 1, 0, -cost});
        return m;
    }

    struct edge {
        int from, to;
        Cap cap, flow;
        Cost cost;
    };

    edge get_edge(int i) {
        int m = int(pos.size());
        assert(0 <= i && i < m);
        auto _e = g[pos[i].first][pos[i].second];
        auto _re = g[_e.to][_e.rev];
        return edge{
            pos[i].first, _e.to, _e.cap + _re.cap, _re.cap, _e.cost,
        };
    }
    std::vector<edge> edges() {
        int m = int(pos.size());
        std::vector<edge> result(m);
        for (int i = 0; i < m; i++) {
            result[i] = get_edge(i);
        }
        return result;
    }

    std::pair<Cap, Cost> flow(int s, int t) {
        return flow(s, t, std::numeric_limits<Cap>::max());
    }
    std::pair<Cap, Cost> flow(int s, int t, Cap flow_limit) {
        return slope(s, t, flow_limit).back();
    }
    std::vector<std::pair<Cap, Cost>> slope(int s, int t) {
        return slope(s, t, std::numeric_limits<Cap>::max());
    }
    std::vector<std::pair<Cap, Cost>> slope(int s, int t, Cap flow_limit) {
        assert(0 <= s && s < _n);
        assert(0 <= t && t < _n);
        assert(s != t);
        // variants (C = maxcost):
        // -(n-1)C <= dual[s] <= dual[i] <= dual[t] = 0
        // reduced cost (= e.cost + dual[e.from] - dual[e.to]) >= 0 for all edge
        std::vector<Cost> dual(_n, 0), dist(_n);
        std::vector<int> pv(_n), pe(_n);
        std::vector<bool> vis(_n);
        auto dual_ref = [&]() {
            std::fill(dist.begin(), dist.end(),
                      std::numeric_limits<Cost>::max());
            std::fill(pv.begin(), pv.end(), -1);
            std::fill(pe.begin(), pe.end(), -1);
            std::fill(vis.begin(), vis.end(), false);
            struct Q {
                Cost key;
                int to;
                bool operator<(Q r) const { return key > r.key; }
            };
            std::priority_queue<Q> que;
            dist[s] = 0;
            que.push(Q{0, s});
            while (!que.empty()) {
                int v = que.top().to;
                que.pop();
                if (vis[v]) continue;
                vis[v] = true;
                if (v == t) break;
                // dist[v] = shortest(s, v) + dual[s] - dual[v]
                // dist[v] >= 0 (all reduced cost are positive)
                // dist[v] <= (n-1)C
                for (int i = 0; i < int(g[v].size()); i++) {
                    auto e = g[v][i];
                    if (vis[e.to] || !e.cap) continue;
                    // |-dual[e.to] + dual[v]| <= (n-1)C
                    // cost <= C - -(n-1)C + 0 = nC
                    Cost cost = e.cost - dual[e.to] + dual[v];
                    if (dist[e.to] - dist[v] > cost) {
                        dist[e.to] = dist[v] + cost;
                        pv[e.to] = v;
                        pe[e.to] = i;
                        que.push(Q{dist[e.to], e.to});
                    }
                }
            }
            if (!vis[t]) {
                return false;
            }

            for (int v = 0; v < _n; v++) {
                if (!vis[v]) continue;
                // dual[v] = dual[v] - dist[t] + dist[v]
                //         = dual[v] - (shortest(s, t) + dual[s] - dual[t]) + (shortest(s, v) + dual[s] - dual[v])
                //         = - shortest(s, t) + dual[t] + shortest(s, v)
                //         = shortest(s, v) - shortest(s, t) >= 0 - (n-1)C
                dual[v] -= dist[t] - dist[v];
            }
            return true;
        };
        Cap flow = 0;
        Cost cost = 0, prev_cost = -1;
        std::vector<std::pair<Cap, Cost>> result;
        result.push_back({flow, cost});
        while (flow < flow_limit) {
            if (!dual_ref()) break;
            Cap c = flow_limit - flow;
            for (int v = t; v != s; v = pv[v]) {
                c = std::min(c, g[pv[v]][pe[v]].cap);
            }
            for (int v = t; v != s; v = pv[v]) {
                auto& e = g[pv[v]][pe[v]];
                e.cap -= c;
                g[v][e.rev].cap += c;
            }
            Cost d = -dual[s];
            flow += c;
            cost += c * d;
            if (prev_cost == d) {
                result.pop_back();
            }
            result.push_back({flow, cost});
            prev_cost = cost;
        }
        return result;
    }

  private:
    int _n;

    struct _edge {
        int to, rev;
        Cap cap;
        Cost cost;
    };

    std::vector<std::pair<int, int>> pos;
    std::vector<std::vector<_edge>> g;
};

}  // namespace atcoder

using namespace atcoder;
int main(){
    lint n,m;
    cin>>n>>m;
    vector<string>s(n);
    rep(i,n){
        cin>>s[i];
    }
    lint cnt=0;
    mcf_graph<lint,lint> mf(n*m*2+2);
    rep(i,n)rep(j,m){
        if(s[i][j]!='o')continue;
        cnt++;
        mat v(n,vec(m,-1));
        queue<pair<lint,lint>>que;
        que.emplace(i,j);
        v[i][j]=0;
        while(!que.empty()){
            auto [px,py]=que.front();
            que.pop();
            if(px!=n-1){
                if(s[px+1][py]!='#'&&v[px+1][py]==-1){
                    v[px+1][py]=v[px][py]+1;
                    que.emplace(px+1,py);
                }
            }
            if(py!=m-1){
                if(s[px][py+1]!='#'&&v[px][py+1]==-1){
                    v[px][py+1]=v[px][py]+1;
                    que.emplace(px,py+1);
                }
            }
        }
        rep(s,n)rep(t,m){
            if(v[s][t]!=-1){
                mf.add_edge(i*m+j,n*m+s*m+t,1,1000000-v[s][t]);
            }
        }
    }
    rep(i,n)rep(j,m){
        mf.add_edge(2*n*m,i*m+j,1,0);
        mf.add_edge(n*m+i*m+j,2*n*m+1,1,0);
    }
    cout<<cnt*1000000-mf.flow(2*n*m,2*n*m+1).second<<endl;
}


Measured memory_bytes: 9024