#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define FOR(i, a, b) for (int i = a; i < (b); i++)
#define F0R(i, a) for (int i = 0; i < (a); i++)
#define F0R1(i, a) for (int i = 1; i <= (a); i++)
#define FORd(i, a, b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i, a) for (int i = (a)-1; i >= 0; i--)
#define F0Rd1(i, a) for (int i = a; i > 0; i--)
#define SORT(vec) sort(vec.begin(), vec.end())
#define S0RT(arr, n) sort(arr, arr + n)
#define pA first
#define pB second
#define MOD 1000000007
#define nl "\n"
#define pb push_back
int n, steps, rootX, rootY, homeX, homeY;
vector<pii> adj[800][800];
bool vis[800][800];
int dist[800][800];
bool visBee[800][800];
int distBee[800][800];
bool blocked[800][800];
bool blocked1[800][800];
vector<pii> hives;
void bfsBees() {
queue<pii> bfsQueue;
for (pii root : hives) {
visBee[root.pA][root.pB] = true;
bfsQueue.push(root);
distBee[root.pA][root.pB] = 0;
}
while (!bfsQueue.empty()) {
pii node = bfsQueue.front();
bfsQueue.pop();
for (pii neighbor : adj[node.pA][node.pB]) {
if (!visBee[neighbor.pA][neighbor.pB] && !(neighbor.pA == homeX && neighbor.pB == homeY)) {
visBee[neighbor.pA][neighbor.pB] = true;
bfsQueue.push(neighbor);
distBee[neighbor.pA][neighbor.pB] = distBee[node.pA][node.pB] + 1;
}
}
}
}
bool bfs(int eatHoney) {
FOR(i, 0, n) {
FOR(j, 0, n) {
vis[i][j] = false;
visBee[i][j] = false;
dist[i][j] = 1e9;
distBee[i][j] = 1e9;
blocked1[i][j] = false;
}
}
queue<pii> bfsQueue;
vis[rootX][rootY] = true;
dist[rootX][rootY] = 0;
bfsQueue.push(pii(rootX, rootY));
bfsBees();
while (!bfsQueue.empty()) {
pii node = bfsQueue.front();
bfsQueue.pop();
for (pii neighbor : adj[node.pA][node.pB]) {
if (!vis[neighbor.pA][neighbor.pB]) {
vis[neighbor.pA][neighbor.pB] = true;
bfsQueue.push(neighbor);
dist[neighbor.pA][neighbor.pB] = dist[node.pA][node.pB] + 1;
}
}
}
FOR(i, 0, n) {
FOR(j, 0, n) {
if (((double)dist[i][j])/steps >= distBee[i][j] - eatHoney){
blocked1[i][j] = true;
}
}
}
FOR(i, 0, n) {
FOR(j, 0, n) {
vis[i][j] = false;
dist[i][j] = 1e9;
}
}
bfsQueue = queue<pii>();
vis[rootX][rootY] = true;
bfsQueue.push(pii(rootX, rootY));
dist[rootX][rootY] = 0;
while (!bfsQueue.empty()) {
pii node = bfsQueue.front();
bfsQueue.pop();
if (blocked1[node.pA][node.pB]) {
continue;
}
for (pii neighbor : adj[node.pA][node.pB]) {
if (!vis[neighbor.pA][neighbor.pB] && !blocked1[neighbor.pA][neighbor.pB]) {
vis[neighbor.pA][neighbor.pB] = true;
bfsQueue.push(neighbor);
dist[neighbor.pA][neighbor.pB] = dist[node.pA][node.pB] + 1;
}
}
}
return (dist[homeX][homeY] != 1e9);
}
void gridAdj() {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (!blocked[i][j]) {
if (i > 0 && !blocked[i - 1][j]) {
adj[i][j].pb(pii(i - 1, j));
}
if (i < n - 1 && !blocked[i + 1][j]) {
adj[i][j].pb(pii(i + 1, j));
}
if (j > 0 && !blocked[i][j - 1]) {
adj[i][j].pb(pii(i, j - 1));
}
if (j < n - 1 && !blocked[i][j + 1]) {
adj[i][j].pb(pii(i, j + 1));
}
}
}
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> steps;
for (int i = 0; i < n; i++) {
string s;
cin >> s;
FOR(j, 0, n) {
if (s[j] == 'T') {
blocked[i][j] = true;
} else if (s[j] == 'M') {
rootX = i;
rootY = j;
} else if (s[j] == 'D') {
homeX = i;
homeY = j;
} else if (s[j] == 'H') {
hives.pb(pii(i, j));
}
}
}
gridAdj();
int l = 0;
int r = 1e6;
int ans = l - 1;
while (l <= r) {
ll mid = (r + l) / 2;
if (bfs(mid)) {
ans = mid;
l = mid + 1;
} else {
r = mid - 1;
}
}
cout << ans << nl;
}
