#include <bits/stdc++.h>
using namespace std;
#define c(X, Y) (X * N + Y)
const int INF = 1e8;
const int di[4] = {-1, 1, 0, 0};
const int dj[4] = {0, 0, -1, 1};
int N, S, d[1<<20], ans = -1, e, r;
string g[1<<10];
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> N >> S;
for(int i = 0; i < N; i++)
cin >> g[i];
for(int b = r = 20; --b >= 0; ) {
ans += 1 << b;
fill(d, d + N * N, INF);
queue<int> p, q;
for(int i = 0; i < N; i++) {
for(int j = 0; j < N; j++) {
if(g[i][j] == 'D')
e = c(i, j);
if(g[i][j] == 'M')
d[c(i, j)] = 0, q.push(c(i, j));
if(g[i][j] == 'H')
d[c(i, j)] = -1, p.push(c(i, j));
}
}
int ext = ans;
while(!empty(q)) {
int lim = ext-- > 0 ? 0 : d[q.front()] + S;
for(int t : {1, -1}) {
while(!empty(q) && (t * d[q.front()]) < lim) {
int k = q.front(), i = k / N, j = k % N; q.pop();
for(int s = 0; s < 4; s++) {
int x = i + di[s], y = j + dj[s], z = x * N + y;
if(min(x, y) < 0 || max(x, y) >= N || d[z] != INF) continue;
if(g[x][y] & 1 || (t > 0 && z == e))
d[z] = d[k] + t, q.push(z);
}
}
swap(p, q);
if(!empty(q)) lim = 1 - d[q.front()];
}
}
if(d[e] == INF)
ans -= 1 << b;
}
cout << ans;
}
