//刘汝佳模板
#include <iostream>
#include <cstring>
#include <algorithm>
#include <cstdio>
#include <vector>
#include <cmath>
#include <queue>
using namespace std;
const int MAXN = 400;
const int MAXM = 200000;
const int INF = 0x3f3f3f3f;
struct Edge
{
    int from,to,cap,cost,flow;
    Edge(int u,int v,int c,int f,int w):from(u),to(v),cap(c),cost(f),flow(w){}
};
vector<Edge> edge;
vector<int> g[MAXN];
int inq[MAXN],d[MAXN],p[MAXN],a[MAXN];
int NN,MM;
int topH,topP;
struct point
{
    int x,y;
}H[MAXN],P[MAXN];

void input()
{
    char ch;
    topH = topP = 0;
    for(int i = 1; i <= NN; i++)
    {
        for(int j = 1; j <= MM; j++)
        {
            scanf("%c",&ch);
            if(ch == ‘H‘)
            {
                topH++;
                H[topH].x = i;
                H[topH].y = j;
            }
            else if(ch == ‘m‘)
            {
                topP++;
                P[topP].x = i;
                P[topP].y = j;
            }
        }
        getchar();
    }
}
void AddEdge(int from, int to, int cap, int cost)
{
    edge.push_back(Edge(from,to,cap,cost,0));
    edge.push_back(Edge(to,from,0,-cost,0));
    int m = edge.size();
    g[from].push_back(m - 2);
    g[to].push_back(m - 1);
}
int MCMF(int s,int t,int& flow, int& cost)
{

    for(int i = 0; i < MAXN; i++)
        d[i] = INF;
    memset(inq, 0, sizeof(inq));
    d[s] = 0;
    inq[s] = 1;
    p[s] = 0;
    a[s] = INF;

    queue<int> myque;
    myque.push(s);
    while(myque.empty() == 0)
    {
        int u = myque.front();
        myque.pop();
        inq[u] = 0;
        for(int i = 0; i < (int)g[u].size(); i++)
        {
            Edge e = edge[ g[u][i] ];
            if(e.cap > e.flow && d[e.to] > d[u] + e.cost)
            {
                d[e.to] = d[u] + e.cost;
                p[e.to] = g[u][i];
                a[e.to] = min(a[u], e.cap - e.flow);
                if(inq[e.to] == 0)
                {
                    myque.push(e.to);
                    inq[e.to] = 1;
                }
            }
        }
    }
    if(d[t] == INF)
        return false;
    flow += a[t];
    cost += d[t] * a[t];

    for(int u = t; u != s; u = edge[ p[u] ].from)
    {
        edge[ p[u] ].flow += a[t];
        edge[ p[u] ^ 1].flow -= a[t];
    }
    return true;

}
int creatGraph()
{
    int ans = 0,flow = 0;
    int MN = topH + topP;
    for(int i = 1; i <= topP; i++)
    {
        for(int j = 1; j <= topH; j++)
        {
            int t = abs(H[i].x - P[j].x) + abs(H[i].y - P[j].y);  //距离最为费用
            AddEdge(i,topP + j, 1, t);   // 边i到topP+j，把所有H.m点都排号序号
        }
    }

    for(int i = 1; i <= topP; i++)
        AddEdge(MN + 1, i, 1, 0);     //源点到M点
    for(int i = topP + 1; i <= MN; i++)
        AddEdge(i, MN + 2, 1,0);     // H点到汇点
    while(MCMF(MN + 1, MN + 2, flow, ans) );
    return ans;
}
int main()
{
    while(scanf("%d%d",&NN,&MM) != EOF)
    {
        if(NN == 0 && MM == 0)
            break;
        getchar();
        for(int i = 1; i < MAXN; i++)
            g[i].clear();
        edge.clear();
        input();
        printf("%d\n",creatGraph());
    }
    return 0;
}