#include <iostream>

#include <cstdio>

#include <sstream>

#include <cstring>

#include <map>

#include <cctype>

#include <set>

#include <vector>

#include <stack>

#include <queue>

#include <algorithm>

#include <cmath>

#include <bitset>

#define rap(i, a, n) for(int i=a; i<=n; i++)

#define rep(i, a, n) for(int i=a; i<n; i++)

#define lap(i, a, n) for(int i=n; i>=a; i--)

#define lep(i, a, n) for(int i=n; i>a; i--)

#define rd(a) scanf("%d", &a)

#define rlld(a) scanf("%lld", &a)

#define rc(a) scanf("%c", &a)

#define rs(a) scanf("%s", a)

#define pd(a) printf("%d\n", a);

#define plld(a) printf("%lld\n", a);

#define pc(a) printf("%c\n", a);

#define ps(a) printf("%s\n", a);

#define MOD 2018

#define LL long long

#define ULL unsigned long long

#define Pair pair<int, int>

#define mem(a, b) memset(a, b, sizeof(a))

#define _  ios_base::sync_with_stdio(0),cin.tie(0)

//freopen("1.txt", "r", stdin);

using namespace std;

const int maxn = , INF = 0x7fffffff, LL_INF = 0x7fffffffffffffff;

int n, m, s, t, flow, value;

char str[][];

int head[maxn], d[maxn], cnt, vis[maxn], p[maxn], f[maxn], di[maxn];

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

vector<int> g;

vector<int> ff;

void bfs(int s)

{

    mem(di, );

    queue<int> Q;

    Q.push(s);

    di[s] = ;

    while(!Q.empty())

    {

        int u = Q.front(); Q.pop();

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

        {

            int v = u + dis[i][] * m + dis[i][];

            if(u % m ==  && i ==  || (u - ) % m ==  && i == ) continue;

            if(v <  || v > n * m || di[v]) continue;

            di[v] = di[u] + ;

            Q.push(v);

        }

    }

}

struct node

{

    int u, v, c, w, next;

}Node[maxn];

void add_(int u, int v, int w, int c)

{

    Node[cnt].u = u;

    Node[cnt].v = v;

    Node[cnt].w = w;

    Node[cnt].c = c;

    Node[cnt].next = head[u];

    head[u] = cnt++;

}

void add(int u, int v, int w, int c)

{

    add_(u, v, w, c);

    add_(v, u, -w, );

}

int spfa()

{

    for(int i = ; i < maxn; i++) d[i] = INF;

    queue<int> Q;

    mem(vis, );

    mem(p, -);

    Q.push(s);

    vis[s] = ;

    d[s] = ;

    p[s] = ; f[s] = INF;

    while(!Q.empty())

    {

        int u = Q.front(); Q.pop();

        vis[u] = ;

      //  cout << u << endl;

        for(int i = head[u]; i != -; i = Node[i].next)

        {

            node e = Node[i];

            //cout << e.v << endl;

            if(d[e.v] > d[u] + e.w && e.c > )

            {

                d[e.v] = d[u] + e.w;

                p[e.v] = i;

                f[e.v] = min(f[u], e.c);

                if(!vis[e.v])

                {

                    vis[e.v] = ;

                    Q.push(e.v);

               //     cout << 11111 << endl;

                }

            }

        }

    }

    if(p[t] == -) return ;

    flow += f[t]; value += f[t] * d[t];

    for(int i = t; i != s; i = Node[p[i]].u)

    {

        Node[p[i]].c -= f[t];

        Node[p[i] ^ ].c += f[t];

    }

    return ;

}

void max_flow()

{

    flow = value = ;

    while(spfa());

    printf("%d\n", value);

}

int main()

{

    while(cin >> n >> m && n + m)

    {

        s = , t = n * m + ;

        mem(head, -);

        cnt = ;

        g.clear(); ff.clear();

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

        {

            scanf("%s", str[i] + );

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

            {

                if(str[i][j] == 'm')

                    g.push_back((i - ) * m + j), add(s, (i - ) * m + j, , );

                else if(str[i][j] == 'H')

                    ff.push_back((i - ) * m + j), add((i - ) * m + j, t, , );

            }

        }

        for(int i = ; i < g.size(); i++)

        {

            bfs(g[i]);

            for(int j = ; j < ff.size(); j++)

            {

                add(g[i], ff[j], di[ff[j]] - , );

               // cout << g[i] << "  " << ff[j] << "  " << di[ff[j]] - 1 << endl;

            }

        }

        max_flow();

    }

    return ;

}