// Source: https://usaco.guide/general/io
#include <bits/stdc++.h>
#define ll int
#define ld long double
#define ln "\n"
#define ff first
#define ss second
#define INF 2e9
using namespace std;
void solve(){
ll n, s; cin >> n >> s;
vector<vector<char>> gr(n, vector<char>(n));
vector<pair<ll, ll>> hvs;
pair<ll, ll> bcor, hcor;
for (ll i=0; i<n; i++){
for (ll j=0; j<n; j++){
cin >> gr[i][j];
if (gr[i][j]=='H'){
hvs.push_back({i, j});
}else if (gr[i][j]=='M'){
bcor = {i, j};
}else if (gr[i][j]=='D'){
hcor = {i, j};
}
}
}
vector<vector<ll>> hpath(n, vector<ll>(n, INF));
auto bfs1 = [&](pair<ll, ll> cord){
hpath[cord.ff][cord.ss]=1;
vector<vector<ll>> vi(n, vector<ll>(n, INF));
queue<pair<ll, ll>> q;
q.push(cord);
vi[cord.ff][cord.ss]=1;
while (!q.empty()){
pair<ll, ll> cur = q.front();
q.pop();
if (cur.ff>0 and vi[cur.ff-1][cur.ss]==INF and gr[cur.ff-1][cur.ss]!='T' and gr[cur.ff-1][cur.ss]!='D' and gr[cur.ff-1][cur.ss]!='H'){
vi[cur.ff-1][cur.ss]=vi[cur.ff][cur.ss]+1;
hpath[cur.ff-1][cur.ss]=min(hpath[cur.ff-1][cur.ss], vi[cur.ff-1][cur.ss]);
q.push({cur.ff-1, cur.ss});
}
if (cur.ss>0 and vi[cur.ff][cur.ss-1]==INF and gr[cur.ff][cur.ss-1]!='T' and gr[cur.ff][cur.ss-1]!='D' and gr[cur.ff][cur.ss-1]!='H'){
vi[cur.ff][cur.ss-1]=vi[cur.ff][cur.ss]+1;
hpath[cur.ff][cur.ss-1]=min(hpath[cur.ff][cur.ss-1], vi[cur.ff][cur.ss-1]);
q.push({cur.ff, cur.ss-1});
}
if (cur.ff+1<n and vi[cur.ff+1][cur.ss]==INF and gr[cur.ff+1][cur.ss]!='T' and gr[cur.ff+1][cur.ss]!='D' and gr[cur.ff+1][cur.ss]!='H'){
vi[cur.ff+1][cur.ss]=vi[cur.ff][cur.ss]+1;
hpath[cur.ff+1][cur.ss]=min(hpath[cur.ff+1][cur.ss], vi[cur.ff+1][cur.ss]);
q.push({cur.ff+1, cur.ss});
}
if (cur.ss+1<n and vi[cur.ff][cur.ss+1]==INF and gr[cur.ff][cur.ss+1]!='T' and gr[cur.ff][cur.ss+1]!='D' and gr[cur.ff][cur.ss+1]!='H'){
vi[cur.ff][cur.ss+1]=vi[cur.ff][cur.ss]+1;
hpath[cur.ff][cur.ss+1]=min(hpath[cur.ff][cur.ss+1], vi[cur.ff][cur.ss+1]);
q.push({cur.ff, cur.ss+1});
}
}
};
auto bfs2 = [&](ll wt) -> bool{
pair<ll, ll> cord = bcor;
if (hpath[cord.ff][cord.ss]-1<wt) {
// cout << "Fail at start: " << hpath[cord.ff][cord.ss] << " <: " << cord.ff << "," << cord.ss << " -> " << wt << ln;
return 0;
}
vector<vector<ll>> vi(n, vector<ll>(n, INF));
queue<pair<ll, ll>> q;
q.push(cord);
vi[cord.ff][cord.ss]=wt;
while (!q.empty()){
pair<ll, ll> cur = q.front();
q.pop();
// cout << "(" << cur.ss << "," << cur.ff << ") -> hpath=" << hpath[cur.ff][cur.ss] << "; mdist=" << vi[cur.ff][cur.ss]-wt << "; enters at=" << (ceil((ld)(vi[cur.ff][cur.ss]-wt)/(ld)s)+wt) << "; " << " bee comes in=" << hpath[cur.ff][cur.ss] << ln;
if (cur.ff>0 and vi[cur.ff-1][cur.ss]==INF and gr[cur.ff-1][cur.ss]!='T' and gr[cur.ff-1][cur.ss]!='H' and (ceil((ld)(vi[cur.ff][cur.ss]-wt+1)/(ld)s)+wt)<(hpath[cur.ff-1][cur.ss])){
// cout << (hpath[cur.ff-1][cur.ss]-(vi[cur.ff][cur.ss]-wt)/s-1) << " <- " << cur.ss << "," << cur.ff << " to U: cmx " << vi[cur.ff][cur.ss] << " Dist from bear: " << vi[cur.ff][cur.ss]-wt+1 << ln;
vi[cur.ff-1][cur.ss]=vi[cur.ff][cur.ss]+1;
q.push({cur.ff-1, cur.ss});
}
if (cur.ss>0 and vi[cur.ff][cur.ss-1]==INF and gr[cur.ff][cur.ss-1]!='T' and gr[cur.ff][cur.ss-1]!='H' and (ceil((ld)(vi[cur.ff][cur.ss]-wt+1)/(ld)s)+wt)<(hpath[cur.ff][cur.ss-1])){
// cout << (hpath[cur.ff][cur.ss-1]-(vi[cur.ff][cur.ss]-wt)/s-1) << " <- " << cur.ss << "," << cur.ff << " to L: cmx " << vi[cur.ff][cur.ss] << " Dist from bear: " << vi[cur.ff][cur.ss]-wt+1 << ln;
vi[cur.ff][cur.ss-1]=vi[cur.ff][cur.ss]+1;
q.push({cur.ff, cur.ss-1});
}
if (cur.ff+1<n and vi[cur.ff+1][cur.ss]==INF and gr[cur.ff+1][cur.ss]!='T' and gr[cur.ff+1][cur.ss]!='H' and (ceil((ld)(vi[cur.ff][cur.ss]-wt+1)/(ld)s)+wt)<(hpath[cur.ff+1][cur.ss])){
// cout << (hpath[cur.ff+1][cur.ss]-(vi[cur.ff][cur.ss]-wt)/s-1) << " <- " << cur.ss << "," << cur.ff << " to D: cmx " << vi[cur.ff][cur.ss] << " Dist from bear: " << vi[cur.ff][cur.ss]-wt+1 << ln;
vi[cur.ff+1][cur.ss]=vi[cur.ff][cur.ss]+1;
q.push({cur.ff+1, cur.ss});
}
if (cur.ss+1<n and vi[cur.ff][cur.ss+1]==INF and gr[cur.ff][cur.ss+1]!='T' and gr[cur.ff][cur.ss+1]!='H' and (ceil((ld)(vi[cur.ff][cur.ss]-wt+1)/(ld)s)+wt)<(hpath[cur.ff][cur.ss+1])){
// cout << (hpath[cur.ff][cur.ss+1]-(vi[cur.ff][cur.ss]+1-wt)/s-1) << " <- " << cur.ss << "," << cur.ff << " to R: cmx " << vi[cur.ff][cur.ss] << " Dist from bear: " << vi[cur.ff][cur.ss]-wt+1 << ln;
vi[cur.ff][cur.ss+1]=vi[cur.ff][cur.ss]+1;
q.push({cur.ff, cur.ss+1});
}
}
if (vi[hcor.ff][hcor.ss]<INF) return 1;
else return 0;
};
for (auto hive:hvs){
bfs1(hive);
}
ll l=-1, r=n*n+1;
while (l+1<r){
ll mid = (l+r)/2;
if (bfs2(mid)) {
l=mid;
// cout << mid << " with T" << ln;
}
else {
r=mid;
// cout << mid << " with F" << ln;
}
}
cout << l << ln;
}
int main() {
ll t=1;
// cin >> t;
while (t--) solve();
}
