#include<cstdio>

#include<iostream>

#include<queue>

#include<cstring>

#include<algorithm>

#include<cctype>

using namespace std;

typedef long long ll;

const int INF=1e9;

const int N=;

const int M=;

inline int read(){

    int X=,w=;char ch=;

    while(!isdigit(ch)){w|=ch=='-';ch=getchar();}

    while(isdigit(ch))X=(X<<)+(X<<)+(ch^),ch=getchar();

    return w?-X:X;

}

struct node{

    int nxt;

    int to;

    int w;

    int b;

}edge[M];

int head[N],cnt=-;

void add(int u,int v,int w,int b){

    cnt++;

    edge[cnt].to=v;

    edge[cnt].w=w;

    edge[cnt].b=b;

    edge[cnt].nxt=head[u];

    head[u]=cnt;

    return;

}

int dis[N];

bool vis[N];

inline bool spfa(int s,int t,int n){

    deque<int>q;

    memset(vis,,sizeof(vis));

    for(int i=;i<=n;i++)dis[i]=INF;

    dis[t]=;q.push_back(t);vis[t]=;

    while(!q.empty()){

    int u=q.front();

    q.pop_front();vis[u]=;

    for(int i=head[u];i!=-;i=edge[i].nxt){

        int v=edge[i].to;

        int b=edge[i].b;

        if(edge[i^].w&&dis[v]>dis[u]-b){

        dis[v]=dis[u]-b;

        if(!vis[v]){

            vis[v]=;

            if(!q.empty()&&dis[v]<dis[q.front()]){

            q.push_front(v);

            }else{

            q.push_back(v);

            }

        }

        }

    }

    }

    return dis[s]<INF;

}

int ans=;

int dfs(int u,int flow,int m){

    if(u==m){

    vis[m]=;

    return flow;

    }

    int res=,delta;

    vis[u]=;

    for(int e=head[u];e!=-;e=edge[e].nxt){

        int v=edge[e].to;

    int b=edge[e].b;

        if(!vis[v]&&edge[e].w&&dis[u]-b==dis[v]){

            delta=dfs(v,min(edge[e].w,flow-res),m);

            if(delta){

                edge[e].w-=delta;

                edge[e^].w+=delta;

                res+=delta;

        ans+=delta*b;

                if(res==flow)break;

            }

        }

    }

    return res;

}

inline int costflow(int S,int T,int n){

    while(spfa(S,T,n)){

    do{

        memset(vis,,sizeof(vis));

        dfs(S,INF,T);

    }while(vis[T]);

    }

    return ans;

}

int num1=,num2=;

int mp[][];

int pos[][];

int pdis[][];

bool walk[][];

int dx[]={,-,,};

int dy[]={,,-,};

void bfs(int xx,int yy,int n,int m){

    queue<int>q1,q2,q3,q4;

    memset(walk,,sizeof(walk));

    memset(pdis,,sizeof(pdis));

    pdis[xx][yy]=;

    q1.push(xx);q2.push(yy);

    walk[xx][yy]=;

    while(!q1.empty()){

    int x=q1.front(),y=q2.front();

    q1.pop(),q2.pop();

    if(mp[x][y]>){

        q3.push(x);q4.push(y);

    }

    for(int i=;i<;i++){

        int nx=x+dx[i],ny=y+dy[i];

        if(nx<=||ny<=||nx>n||ny>m||walk[nx][ny])continue;

        walk[nx][ny]=;

        pdis[nx][ny]=pdis[x][y]+;

        q1.push(nx);q2.push(ny);

    }

    }

    while(!q3.empty()){

    int nx=q3.front(),ny=q4.front();

    q3.pop();q4.pop();

    add(pos[xx][yy],mp[nx][ny]+num1,,pdis[nx][ny]);

    add(mp[nx][ny]+num1,pos[xx][yy],,-pdis[nx][ny]);

    }

    return;

}

void restart(){

    memset(head,-,sizeof(head));

    memset(mp,,sizeof(mp));

    memset(pos,,sizeof(pos));

    cnt=-;

    ans=;

    num1=;

    num2=;

    return;

}

int main(){

    int n,m;

    while(scanf("%d%d",&n,&m)!=EOF&&n&&m){

    restart();

    for(int i=;i<=n;i++){

        for(int j=;j<=m;j++){

        char ch;

        cin>>ch;

        if(ch=='m'){

            num1++;

            mp[i][j]=-;

            pos[i][j]=num1;

        }else if(ch=='H'){

            num2++;

            mp[i][j]=num2;

        }

        }

    }

    int S=num1+num2+,T=S+;

    for(int i=;i<=num1;i++){

        add(S,i,,);

        add(i,S,,);

    }

    for(int i=;i<=num2;i++){

        add(i+num1,T,,);

        add(T,i+num1,,);

    }

    for(int i=;i<=n;i++){

        for(int j=;j<=m;j++){

        if(mp[i][j]==-){

            bfs(i,j,n,m);

        }

        }

    }

    printf("%d\n",costflow(S,T,T));

    }

    return ;

}