#include <iostream>
#include <vector>
#include <queue>
#define pii pair<int, int>
using namespace std;
int N, S;
int mR, mC, dR, dC;
char grid[801][801];
int minHiveDist[801][801], minBearDist[801][801];
const int dx[4] = { -1, 1, 0, 0 };
const int dy[4] = { 0, 0, -1, 1 };
bool isValid(int r, int c) { return 0 <= r && r < N && 0 <= c && c < N; }
vector<vector<bool>> visited;
void bfs(vector<pii> initialCoords) {
queue<pair<pii, int>> q;
visited.clear(); visited.resize(N, vector<bool>(N));
for (pii p : initialCoords) {
q.push({ p, 0 }); visited[p.first][p.second] = true;
}
while (!q.empty()) {
pii loc = q.front().first; int dist = q.front().second; q.pop();
minHiveDist[loc.first][loc.second] = dist;
for (int i = 0; i < 4; i++) {
int r = loc.first + dx[i], c = loc.second + dy[i];
if (isValid(r, c) && !visited[r][c] && grid[r][c] != 'T' && grid[r][c] != 'D') {
visited[r][c] = true;
q.push({ {r, c}, dist + S });
}
}
}
}
void bfs2(int startR, int startC, int wait) {
visited.clear(); visited.resize(N, vector<bool>(N));
if (minHiveDist[startR][startC] <= wait * S) return;
queue<pair<pii, int>> q; q.push({ {startR, startC}, wait * S });
visited[startR][startC] = true;
while (!q.empty()) {
pii loc = q.front().first; int dist = q.front().second; q.pop();
minBearDist[loc.first][loc.second] = dist;
for (int i = 0; i < 4; i++) {
int r = loc.first + dx[i], c = loc.second + dy[i];
if (isValid(r, c) && !visited[r][c] && grid[r][c] != 'T') {
if (dist + 1 < minHiveDist[r][c]) {
visited[r][c] = true;
q.push({ {r, c}, dist + 1 });
}
}
}
}
}
bool works(int wait) {
bfs2(mR, mC, wait);
return visited[dR][dC];
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> N >> S;
for (int i = 0; i < N; i++)
for (int j = 0; j < N; j++)
cin >> grid[i][j];
vector<pii> hives;
for (int i = 0; i < N; i++) {
for (int j = 0; j < N; j++) {
if (grid[i][j] == 'H') hives.push_back({ i, j });
if (grid[i][j] == 'M') { mR = i; mC = j; }
if (grid[i][j] == 'D') { dR = i; dC = j; }
}
}
bfs(hives); minHiveDist[dR][dC] = (int)1e9;
int low = 0, high = N * N;
while (low < high) {
int mid = (low + high + 1) / 2;
if (works(mid)) low = mid;
else high = mid - 1;
} cout << (works(low) ? low : low - 1) << endl;
}
