#include<bits/stdc++.h>
using namespace std;
int n,s, bee[808][808], xx[] = {0, 0, -1, 1}, xy[] = {-1, 1, 0, 0}, bear[808][808], ans;
char mp[808][808];
pair<int, int> start, en;
queue<tuple<int, int, int>> q;
bool solve(int mid){
for(int i = 1; i<=n; ++i) for(int j = 1; j<=n; ++j) bee[i][j] = bear[i][j] = 1e9;
for(int i = 1; i<=n; ++i){
for(int j = 1; j<=n; ++j){
if(mp[i][j] == 'H'){
bee[i][j] = 0;
q.emplace(i, j, 0);
}
}
}
while(!q.empty()){
int x = get<0>(q.front()), y = get<1>(q.front()), w = get<2>(q.front());
q.pop();
for(int i = 0; i<4; ++i){
int nx = x + xx[i];
int ny = y + xy[i];
if(nx < 1 || n < 1 || nx > n || ny > n || mp[nx][ny] == 'T') continue;
if(bee[nx][ny] > w + 1){
bee[nx][ny] = w + 1;
q.emplace(nx, ny, w + 1);
}
}
}
bear[start.first][start.second] = mid;
q.emplace(start.first, start.second, mid);
while(!q.empty()){
int x = get<0>(q.front()), y = get<1>(q.front()), w = get<2>(q.front()); q.pop();
if(x == en.first && y == en.second) return true;
for(int i = 0; i<4; ++i){
int nx = x + xx[i];
int ny = y + xy[i];
if(nx < 1 || ny < 1 || nx > n || ny > n || mp[nx][ny] == 'T') continue;
if(bear[nx][ny] > w + 1){
int times = ((w + 1) / s) + ((w + 1) % s != 0);
if(bee[nx][ny] <= times) continue;
bear[nx][ny] = w + 1;
q.emplace(nx, ny, w+1);
}
}
}
return false;
}
int main(){
cin.tie(nullptr)->sync_with_stdio(false);
cin >> n >> s;
for(int i = 1; i<=n; ++i){
for(int j = 1; j<=n; ++j){
cin >> mp[i][j];
if(mp[i][j] == 'M') start = {i, j};
else if(mp[i][j] == 'D') en = {i, j};
}
}
int l = 1, r = 1e9;
while(l < r){
int mid = (l + r) >> 1;
//cout << mid << ' ';
if(solve(mid)){
ans = mid;
l = mid + 1;
}
else r = mid - 1;
}
cout << ans;
}
