#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << " " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << " " << j << " " << #i << " " << q << " " << #p << endl;
#define show4(x,y) for(auto it:y) cout << it << " "; cout << #x << endl;
typedef pair<int,int>pii;
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
void solve(){
int n,k;
cin >> n >> k;
string arr[n];
vector<pii>hive;
pii st;
pii ed;
for(int x=0;x<n;x++){
cin >> arr[x];
for(int y=0;y<n;y++){
if(arr[x][y]=='M'){
st={x,y};
}
else if(arr[x][y]=='H'){
hive.push_back({x,y});
}
else if(arr[x][y]=='D'){
ed={x,y};
}
}
}
pii dir[4]={
{0,1},
{0,-1},
{1,0},
{-1,0},
};
queue<pii>q;
int dist2[n+5][n+5];
memset(dist2,-1,sizeof(dist2));
for(auto it:hive){
dist2[it.first][it.second]=0;
q.push(it);
}
while(!q.empty()){
pii cur=q.front();
q.pop();
for(auto it:dir){
int nx=cur.first+it.first;
int ny=cur.second+it.second;
if(nx<0||ny<0||nx>=n||ny>=n) continue;
if(dist2[nx][ny]!=-1) continue;
if(arr[nx][ny]=='T') continue;
dist2[nx][ny]=dist2[cur.first][cur.second]+1;
q.push({nx,ny});
}
}
int l=1;
int r=2*n+5;
int best=-1;
int mid;
while(l<=r){
mid=(l+r)/2;
int dist[n+5][n+5];
memset(dist,-1,sizeof(dist));
q.push(st);
bool amos=true;
dist[st.first][st.second]=0;
if(dist2[st.first][st.second]-mid==0) amos=false;
while(!q.empty()){
pii cur=q.front();
q.pop();
for(auto it:dir){
int nx=cur.first+it.first;
int ny=cur.second+it.second;
if(nx<0||ny<0||nx>=n||ny>=n) continue;
if(arr[nx][ny]=='T') continue;
if(dist[nx][ny]!=-1) continue;
int nd=dist[cur.first][cur.second]+1;
if(dist2[nx][ny]==-1||(dist2[nx][ny]-mid)*k>nd){
dist[nx][ny]=nd;
q.push({nx,ny});
}
}
}
//for(int x=0;x<n;x++){
//for(int y=0;y<n;y++){
//cout << dist[x][y] << " ";
//}
//cout << "\n";
//}
//cout << "\n";
//for(int x=0;x<n;x++){
//for(int y=0;y<n;y++){
//cout << dist2[x][y] << " ";
//}
//cout << "\n";
//}
if(amos&&dist[ed.first][ed.second]!=-1){
best=mid;
l=mid+1;
}
else r=mid-1;
}
cout << best << "\n";
}
int32_t main(){
ios::sync_with_stdio(0);
cin.tie(0);
int t=1;
//cin >> t;
while(t--){
solve();
}
}
