#include <bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define pb push_back
#define FIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
using namespace std;
typedef pair <ll, ll> pii;
const int N = 807, inf = 1e9;
int dx[] = {0, 1, 0, -1};
int dy[] = {1, 0, -1, 0};
int n, S, stx, sty, enx, eny;
char mat[N][N];
int bee[N][N], bio[N][N];
int main () {
FIO;
cin >> n >> S;
vector <pii> v;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
cin >> mat[i][j];
if (mat[i][j] == 'M') stx = i, sty = j;
if (mat[i][j] == 'D') enx = i, eny = j;
if (mat[i][j] == 'H') v.pb({i, j});
}
}
for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) bee[i][j] = inf;
for (int i = 0; i <= n+1; i++) bee[i][0] = bee[i][n+1] = bee[0][i] = bee[n+1][i] = -1;
queue <pii> q;
for (auto it : v) {
q.push(it);
bee[it.F][it.S] = 0;
}
while (!q.empty()) {
pii fr = q.front(); q.pop();
int x = fr.F, y = fr.S;
for (int i = 0; i < 4; i++) {
int nx = x + dx[i], ny = y + dy[i];
if (bee[nx][ny] != inf) continue;
if (mat[nx][ny] == 'T' || mat[nx][ny] == 'D') continue;
bee[nx][ny] = bee[x][y] + 1;
q.push({nx, ny});
}
}
int lo = -1, hi = 1e8;
while (!q.empty()) q.pop();
while (lo < hi) {
int mid = (lo + hi + 1) / 2;
if (mid >= bee[stx][sty]) {
hi = mid-1;
continue;
}
memset(bio, -1, sizeof bio);
for (int i = 0; i <= n+1; i++) bio[i][0] = bio[i][n+1] = bio[0][i] = bio[n+1][i] = -2;
bio[stx][sty] = 0;
q.push({stx, sty});
while (!q.empty()) {
pii fr = q.front(); q.pop();
int x = fr.F, y = fr.S;
int d = bio[x][y];
for (int i = 0; i < 4; i++) {
int nx = x + dx[i], ny = y + dy[i];
if (bio[nx][ny] != -1) continue;
if (mat[nx][ny] == 'T' || bee[nx][ny] <= mid+(d+1)/S) continue;
bio[nx][ny] = d + 1;
q.push({nx, ny});
}
}
if (bio[enx][eny] == -1) hi = mid-1;
else lo = mid;
}
cout << lo << "\n";
return 0;
}
