#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define rep(i,l,r) for(int i = (l); i < r; i++)
#define per(i,r,l) for(int i = (r); i >= l; i--)
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define pb push_back
#define ff first
#define ss second
const ll mod = 998244353, maxn = 800 + 5, inf = 1e9 + 5;
struct node{
int x, y, rem, eq;
node(){}
node(int x, int y, int r, int e):
x(x), y(y), rem(r), eq(e){}
};
int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
bool bad[maxn][maxn], vis[maxn][maxn];
int dist_bee[maxn][maxn];
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int n, s; cin >> n >> s;
pair<int, int> st, en;
deque<pair<int, int>> hol;
rep(i,0,n){
rep(j,0,n){
dist_bee[i][j] = inf;
char e; cin >> e;
if(e == 'M'){
st = {i, j};
}
if(e == 'D'){
en = {i, j};
}
if(e == 'H'){
hol.push_back({i, j});
dist_bee[i][j] = 0;
}
if(e == 'H' || e == 'T') bad[i][j] = 1;
}
}
while(sz(hol)){
pair<int, int> p = hol.front(); hol.pop_front();
rep(d,0,4){
int i = p.ff + dx[d], j = p.ss + dy[d];
if(i < 0 || i >= n || j < 0 || j >= n || dist_bee[i][j] != inf || bad[i][j]) continue;
dist_bee[i][j] = dist_bee[p.ff][p.ss] + 1;
hol.pb({i, j});
}
}
dist_bee[en.ff][en.ss] = inf;
// rep(i,0,n){
// rep(j,0,n){
// if(dist_bee[i][j] == inf) cout << -1 << ' ';
// else cout << dist_bee[i][j] << ' ';
// }
// cout << endl;
// }
auto chk = [&](int t) -> bool{
memset(vis, 0, sizeof vis);
deque<node> q;
q.push_back(node(st.ff, st.ss, s, t + 1));
vis[st.ff][st.ss] = 1;
while(sz(q)){
node p = q.front(); q.pop_front();
rep(d,0,4){
int i = p.x + dx[d], j = p.y + dy[d];
if(i < 0 || i >= n || j < 0 || j >= n || vis[i][j] || bad[i][j]) continue;
node r = node(i, j, p.rem - 1, p.eq);
if(!r.rem){
if(dist_bee[i][j] <= p.eq) continue;
r.rem = s, r.eq++;
}
vis[i][j] = 1;
q.push_back(r);
}
}
return vis[en.ff][en.ss];
};
int l = -1, r = 1e6;
while(l + 1 < r){
int mid = (l + r)/2;
if(chk(mid)) l = mid;
else r = mid;
}
cout << l;
return 0;
}
