#include<bits/stdc++.h>
#define ll long long
#define mp make_pair
#define pub push_back
#define pob pop_back
#define ss second
#define ff first
#define ext exit(0)
using namespace std;
int n,s,l,r,x,y,zu[801][801],bo[801][801],ax,ay;
char c[801][801];
void dfs(int i, int j){
queue<pair<pair<int,int>,int> >q;
memset(bo,0,sizeof bo);
q.push(mp(mp(i,j),0));
bo[i][j]=1;
zu[i][j]=0;
while(!q.empty()){
int ii=q.front().ff.ff,jj=q.front().ff.ss,zz=q.front().ss;
if(ii>1 && c[ii-1][jj]!='T' && c[ii-1][jj]!='D' && !bo[ii-1][jj]){
bo[ii-1][jj]=1;
zu[ii-1][jj]=min(zu[ii-1][jj],zz+1);
q.push(mp(mp(ii-1,jj),zz+1));
}
if(ii<n && c[ii+1][jj]!='T' && c[ii+1][jj]!='D' && !bo[ii+1][jj]){
bo[ii+1][jj]=1;
zu[ii+1][jj]=min(zu[ii+1][jj],zz+1);
q.push(mp(mp(ii+1,jj),zz+1));
}
if(jj>1 && c[ii][jj-1]!='T' && c[ii][jj-1]!='D' && !bo[ii][jj-1]){
bo[ii][jj-1]=1;
zu[ii][jj-1]=min(zu[ii][jj-1],zz+1);
q.push(mp(mp(ii,jj-1),zz+1));
}
if(jj<n && c[ii][jj+1]!='T' && c[ii][jj+1]!='D' && !bo[ii][jj+1]){
bo[ii][jj+1]=1;
zu[ii][jj+1]=min(zu[ii][jj+1],zz+1);
q.push(mp(mp(ii,jj+1),zz+1));
}
q.pop();
}
}
bool can(int k){
queue<pair<pair<int,int>,pair<int,int> > >q;
memset(bo,0,sizeof bo);
q.push(mp(mp(x,y),mp(k,0)));
bo[x][y]=1;
while(!q.empty()){
int xx=q.front().ff.ff,yy=q.front().ff.ss,kk=q.front().ss.ff,zz=q.front().ss.ss;
if(zz==s) zz=0,kk++;
else zz++;
if(xx>1 && c[xx-1][yy]!='T' && !bo[xx-1][yy] && zu[xx-1][yy]>kk){
bo[xx-1][yy]=1;
q.push(mp(mp(xx-1,yy),mp(kk,zz)));
}
if(xx<n && c[xx+1][yy]!='T' && !bo[xx+1][yy] && zu[xx+1][yy]>kk){
bo[xx+1][yy]=1;
q.push(mp(mp(xx+1,yy),mp(kk,zz)));
}
if(yy>1 && c[xx][yy-1]!='T' && !bo[xx][yy-1] && zu[xx][yy-1]>kk){
bo[xx][yy-1]=1;
q.push(mp(mp(xx,yy-1),mp(kk,zz)));
}
if(yy<n && c[xx][yy+1]!='T' && !bo[xx][yy+1] && zu[xx][yy+1]>kk){
bo[xx][yy+1]=1;
q.push(mp(mp(xx,yy+1),mp(kk,zz)));
}
q.pop();
}
if(bo[ax][ay]) return 1;
return 0;
}
int main (){
cin>>n>>s;
for(int i=1;i<=n;i++){
for(int j=1;j<=n;j++){
cin>>c[i][j];
if(c[i][j]=='M') x=i,y=j;
if(c[i][j]=='D') ax=i,ay=j;
zu[i][j]=1e9;
}
}
for(int i=1;i<=n;i++) for(int j=1;j<=n;j++) if(c[i][j]=='H') dfs(i,j);
l=0,r=640000;
while(l+1<r){
ll mid=(l+r)/2;
if(can(mid)) l=mid;
else r=mid;
}
if(can(r)) cout<<r;
else cout<<l;
}
