#include<bits/stdc++.h>
using namespace std;
const int INF = 1e9;
int n , s;
vector<string> grid;
vector<pair<int,int>> hiveloc;
pair<int,int> mecholoc;
pair<int,int> mechohome;
vector<vector<int>> beetime;
vector<vector<int>> mechodist;
int dx[4] = {1 , - 1, 0 , 0};
int dy[4] = {0 , 0 , 1 , -1};
bool inside(int x , int y) {
return (x >= 0 && y >= 0 && x < n && y < n && grid[x][y] != 'T' && grid[x][y] != 'D');
}
bool valid(int m) {
vector<vector<bool>> visited(n , vector<bool> (n));
queue<pair<int,int>> q;
q.push({mecholoc.first, mecholoc.second});
int mechtime = m + 1;
if(mechtime > beetime[mecholoc.first][mecholoc.second]) {
return false;
}
while(!q.empty()) {
pair<int,int> cur = q.front();
q.pop();
for(int i = 0;i < 4; i++){
int x = cur.first + dx[i];
int y = cur.second + dy[i];
if(x == mechohome.first && y == mechohome.second) {
visited[x][y] = true;
}
if(!inside(x , y) || visited[x][y] || mechodist[x][y] == INF) {
continue;
}
mechtime = m + mechodist[x][y] / s;
if(mechodist[x][y] % s != 0) {
mechtime++;
}
if(mechtime <= beetime[x][y]) {
q.push({x, y});
visited[x][y] = true;
}
}
}
return visited[mechohome.first][mechohome.second];
}
int main() {
cin >> n >> s;
grid.resize(n);
for(int i = 0;i < n;i++) {
for(int j = 0;j < n; j++) {
cin >> grid[i][j];
if(grid[i][j] == 'H') {
hiveloc.push_back({i , j});
}
else if(grid[i][j] == 'M') {
mecholoc = {i , j};
}
else if(grid[i][j] == 'D') {
mechohome = {i , j};
}
}
}
beetime.assign(n , vector<int>(n , INF));
queue<pair<int,int>> q;
for(auto &x : hiveloc) {
q.push(x);
beetime[x.first][x.second] = 0;
}
while(!q.empty()) {
pair<int,int> cur= q.front();
q.pop();
for(int i = 0;i < 4; i++) {
int x = cur.first + dx[i];
int y = cur.second + dy[i];
if(!inside(x , y) || beetime[x][y] != INF){
continue;
}
beetime[x][y] = beetime[cur.first][cur.second] + 1;
q.push({x , y});
}
}
mechodist.assign(n , vector<int>(n ,INF));
while(!q.empty()) {
q.pop();
}
q.push({mecholoc.first, mecholoc.second});
mechodist[mecholoc.first][mecholoc.second] = 0;
while(!q.empty()) {
pair<int,int> cur = q.front();
q.pop();
for(int i = 0 ;i < 4 ;i++) {
int x = cur.first + dx[i];
int y = cur.second + dy[i];
if(!inside(x ,y)|| mechodist[x][y] != INF) {
continue;
}
mechodist[x][y] = mechodist[cur.first][cur.second] + 1;
q.push({x , y});
}
}
int lo = 0;
int hi = 1e6;
while(lo < hi) {
int m = (lo + hi + 1) / 2;
if(valid(m)) {
lo = m;
}
else {
hi = m - 1;
}
}
int ans = lo;
cout << ans << endl;
}
