#include <bits/stdc++.h>
using namespace std;
#define ld long double
#define ll long long int
#define pi pair<int,int>
#define sz(x) (int)x.size()
#define all(x) begin(x),end(x)
int main()
{
cin.tie(0)->sync_with_stdio(0);
int n,s;cin >> n >> s;
vector<vector<char>> a(n + 1,vector<char>(n + 1));
queue<pair<int,int>> qu;
vector<vector<int>> bdist(n + 1,vector<int>(n + 1));
vector<vector<bool>> bvis(n + 1,vector<bool>(n + 1));
int si = -1,sj = -1,ei = -1,ej = -1;
for(int i=1;i<=n;i++){
for(int j=1;j<=n;j++){
cin >> a[i][j];
if(a[i][j] == 'H'){
bvis[i][j] = true;
qu.push({i,j});
}
if(a[i][j] == 'M'){
si = i;
sj = j;
}
if(a[i][j] == 'D'){
ei = i;
ej = j;
}
}
}
while(sz(qu)){
int ni = qu.front().first,nj = qu.front().second;
//cout << ni << ' ' << nj << '\n';
qu.pop();
for(int i=-1;i<=1;i++) for(int j=-1;j<=1;j++){
if(abs(i) == abs(j)) continue;
int ii = ni + i,jj = nj + j;
if(ii < 1 || ii > n || jj < 1 || jj > n) continue;
if(bvis[ii][jj] || a[ii][jj] == 'T' || a[ii][jj] == 'D') continue;
bvis[ii][jj] = true;
bdist[ii][jj] = bdist[ni][nj] + 1;
qu.push({ii,jj});
}
}
/*
for(int i=1;i<=n;i++){
for(int j=1;j<=n;j++){
cout << (bdist[i][j] == 1e9 ? -1 : bdist[i][j]) << ' ';
}
cout << '\n';
}
cout << "---------------------------------------------\n";
*/
int ans = -1;
int l = 0,r = n * n;
while(l <= r){
int mid = (l + r) >> 1;
if(bdist[si][sj] <= mid){
r = mid - 1;
continue;
}
//cout << mid << '\n';
vector<vector<int>> dist(n + 1,vector<int>(n + 1));
vector<vector<bool>> vis(n + 1,vector<bool>(n + 1));
queue<pair<int,int>> q;
q.push({si,sj});
vis[si][sj] = true;
bool ok = false;
while(sz(q)){
int ni = q.front().first,nj = q.front().second;
q.pop();
for(int i=-1;i<=1;i++) for(int j=-1;j<=1;j++){
if(abs(i) == abs(j)) continue;
int ii = ni + i,jj = nj + j;
if(ii < 1 || ii > n || jj < 1 || jj > n) continue;
if(vis[ii][jj]) continue;
if(a[ii][jj] == 'T' || a[ii][jj] == 'H') continue;
if(bdist[ii][jj] <= mid + (dist[ni][nj] + 1) / s) continue;
vis[ii][jj] = true;
dist[ii][jj] = dist[ni][nj] + 1;
q.push({ii,jj});
}
}
for(int i=-1;i<=1;i++) for(int j=-1;j<=1;j++){
if(abs(i) == abs(j)) continue;
int ii = ei + i,jj = ej + j;
if(ii < 1 || ii > n || jj < 1 || jj > n) continue;
if(a[ii][jj] == 'T' || a[ii][jj] == 'H') continue;
if(!vis[ii][jj]) continue;
if(dist[ii][jj] / s + mid >= bdist[ii][jj]) continue;
ok = true;
}
/*
for(int i=1;i<=n;i++) {
for(int j=1;j<=n;j++) {
cout << dist[i][j] << ' ';
}
cout << '\n';
}
*/
if(ok){
l = mid + 1;
ans = mid;
}
else r = mid - 1;
}
cout << ans;
/*
for(int i=1;i<=n;i++){
for(int j=1;j<=n;j++){
cout << bdist[i][j] << ' ';
}
cout << '\n';
}
*/
return 0;
}
