#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
void World_Final();
void Solve();
int main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr);
if (fopen(taskname".in", "r")) {
freopen(taskname".in", "r", stdin);
freopen(taskname".out", "w", stdout);
}
World_Final();
}
void World_Final(){
int Tests = 1;
//cin >> Tests;
while (Tests --) {
Solve();
}
}
const int MAXN = 805;
int N, S, bee[MAXN][MAXN], bear[MAXN][MAXN]; char G[MAXN][MAXN];
int dx[4] = {0, 0, 1, -1}, dy[4] = {1, -1, 0, 0};
pair<int, int> st, en;
bool query(int rest){
memset(bear, -1, sizeof(bear));
queue<pair<int, int>> q; q.push(st); bear[st.first][st.second] = 0;
while (!q.empty()) {
int u, v; tie(u, v) = q.front();
//cout << u << " " << v << "\n";
q.pop();
for (int i = 0; i < 4; i ++) {
int nu = u + dx[i];
int nv = v + dy[i];
if (nu >= 1 && nu <= N && nv >= 1 && nv <= N) {
if (G[nu][nv] == 'G' && bear[nu][nv] == -1) {
int t = (bear[u][v] + 1)/S;
if (t < bee[nu][nv] - rest) {
bear[nu][nv] = bear[u][v] + 1;
q.push(make_pair(nu, nv));
}
}
if (G[nu][nv] == 'D' && bear[nu][nv] == -1) {
bear[nu][nv] = bear[u][v] + 1;
q.push(make_pair(nu, nv));
}
}
}
}
return bear[en.first][en.second] != -1;
}
void Solve(){
cin >> N >> S;
for (int i = 1; i <= N; i ++) {
for (int j = 1; j <= N; j ++) {
cin >> G[i][j];
}
}
memset(bee, -1, sizeof(bee)); queue<pair<int, int>> q;
for (int i = 1; i <= N; i ++) {
for (int j = 1; j <= N; j ++) {
if (G[i][j] == 'H') {
bee[i][j] = 0;
q.push(make_pair(i, j));
}
if (G[i][j] == 'M') st = make_pair(i, j);
if (G[i][j] == 'D') en = make_pair(i, j);
}
}
while (!q.empty()) {
int u, v; tie(u, v) = q.front();
q.pop();
for (int i = 0; i < 4; i ++) {
int nu = u + dx[i];
int nv = v + dy[i];
if (nu >= 1 && nu <= N && nv >= 1 && nv <= N) {
if ((G[nu][nv] == 'G' || G[nu][nv] == 'M') && bee[nu][nv] == -1) {
bee[nu][nv] = bee[u][v] + 1;
q.push(make_pair(nu, nv));
}
}
}
}
int l = 0, h = 1e9;
while (l <= h) {
int mid = (l + h) / 2;
//cout << mid << "\n";
if (query(mid)) l = mid + 1;
else h = mid - 1;
} cout << h;
}
