#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define task "C"
#define fi first
#define se second
const int dx[] = {-1, 0, 0, +1};
const int dy[] = {0, -1, +1, 0};
const int N = 802;
int n, s;
char a[N][N];
pair<int, int> st, en;
pair<int, int> d[N][N];
pair<int, int> e[N][N];
deque<pair<int, int>> dq;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> s;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++)
d[i][j] = {1e9, -1};
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
cin >> a[i][j];
if (a[i][j] == 'M')
st = make_pair(i, j);
if (a[i][j] == 'D')
en = make_pair(i, j);
if (a[i][j] == 'H') {
d[i][j] = {0, 0};
dq.push_back({i, j});
}
}
}
// FirstBfs();
while (dq.size()) {
auto [u, v] = dq.front();
dq.pop_front();
for (int i = 0; i < 4; i++) {
int x = u + dx[i], y = v + dy[i];
if (x < 1 || x > n) continue;
if (y < 1 || y > n) continue;
if (a[x][y] != 'T') {
if (d[x][y].fi == 1e9) {
d[x][y].fi = d[u][v].fi + 1;
d[x][y].se = d[u][v].se;
dq.push_back({x, y});
}
}
}
}
int l = -1, r = n * n;
while (r - l > 1) {
int mid = l + r >> 1;
bool ok = false;
if (mid < d[st.fi][st.se].fi) {
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++)
e[i][j] = d[i][j];
}
while (dq.size()) dq.pop_back();
e[st.fi][st.se] = {mid, s};
dq.push_back(st);
while (dq.size()) {
auto [u, v] = dq.front();
int cnt = e[u][v].se;
int du = e[u][v].fi;
dq.pop_front();
if (u == en.fi && v == en.se) {
ok = true; break;
}
int w, _c;
if (cnt == s) w = 1, _c = 1;
else w = 0, _c = cnt + 1;
for (int i = 0; i < 4; i++) {
int x = u + dx[i], y = v + dy[i];
if (x < 1 || x > n) continue;
if (y < 1 || y > n) continue;
if (a[x][y] != 'T') {
if (e[x][y].fi > e[u][v].fi + w) {
e[x][y].fi = e[u][v].fi + w;
e[x][y].se = _c;
if (w) dq.push_back({x, y});
else dq.push_front({x, y});
} else if (e[x][y].fi == e[u][v].fi + w) {
if (_c == s && e[x][y].se == 0) continue;
if (e[x][y].se == 0) {
e[x][y].se = _c;
if (w) dq.push_back({x, y});
else dq.push_front({x, y});
} else {
if (e[x][y].se > _c) {
e[x][y].se = _c;
if (w) dq.push_back({x, y});
else dq.push_front({x, y});
}
}
}
}
}
} }
if (ok) l = mid;
else r = mid;
}
cout << l;
}
