#include <bits/stdc++.h>
#define int long long
#define f first
#define s second
using namespace std;
const int MAXN = 810;
char grid[MAXN][MAXN];
int dr[4] = {0,0,1,-1}, dc[4] = {1,-1,0,0},N;
bool goodbees(int r, int c){
return r >= 0 && c >= 0 && r <= N-1 && c <= N-1 && grid[r][c] != 'T' && grid[r][c] != 'D';
}
bool goodmecho(int r, int c){
return r >= 0 && c >= 0 && r <= N-1 && c <= N-1 && grid[r][c] != 'T';
}
const int INF = 1e18;
int32_t main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int S; cin >> N >> S;
queue<pair<int,int>> q;
vector<vector<int>> dist(N,vector<int>(N,INF));
pair<int,int> m,home;
for(int i = 0;i<N;++i){
for(int j = 0;j<N;++j){
cin >> grid[i][j];
if(grid[i][j] == 'H'){
q.push({i,j});
dist[i][j] = 0;
}
else if(grid[i][j] == 'M'){
m.f = i, m.s = j;
}
else if(grid[i][j] == 'D'){
home.f = i, home.s = j;
}
}
}
while(!q.empty()){
int r = q.front().f, c = q.front().s; q.pop();
for(int i = 0;i<4;++i){
int nr = r+dr[i], nc = c+dc[i];
if(goodbees(nr,nc)){
if(dist[nr][nc] > dist[r][c]+1){
dist[nr][nc] = dist[r][c]+1;
q.push({nr,nc});
}
}
}
}
/*vector<vector<int>> mecho(N,vector<int>(N,INF));
mecho[m.f][m.s] = 0; q.push(m);
while(!q.empty()){
int r = q.front().f, c = q.front().s; q.pop();
for(int i = 0;i<4;++i){
int nr = r+dr[i], nc = c+dc[i];
if(goodmecho(nr,nc)){
if(mecho[nr][nc] > mecho[r][c]+1){
mecho[nr][nc] = mecho[r][c]+1;
q.push({nr,nc});
}
}
}
}*/
int lo = 0, hi = dist[m.f][m.s];
vector<vector<int>> D(N,vector<int>(N,INF));
--lo;
while(lo < hi){
int mid = lo+(hi-lo+1)/2; //time
//cout << mid << "\n";
D = vector<vector<int>>(N,vector<int>(N,INF));
q.push(m); D[m.f][m.s] = 0;
while(!q.empty()){
int r = q.front().f, c = q.front().s; q.pop();
//cout << r << " " << c << "\n";
for(int i = 0;i<4;++i){
int nr = r+dr[i], nc = c+dc[i];
if(goodmecho(nr,nc)){
if((D[r][c]+1)/S +mid < dist[nr][nc] && D[r][c]+1 < D[nr][nc]){
D[nr][nc] = D[r][c]+1;
q.push({nr,nc});
}
}
}
}
if(D[home.f][home.s] == INF){
hi = mid-1;
}
else{
lo = mid;
}
}
cout << lo << "\n";
return 0;
}
