#include <bits/stdc++.h>
using namespace std;
int n,s,mx,my,dx,dy;
char mat[800][800];
int dist[800][800],nuedist[800][800];
queue<pair<int,int>> bfs,bfs2;
void expand(int nowx,int nowy,int nex,int ney){
if(nex<0 || nex>=n || ney<0 || ney>=n)return;
if(mat[nex][ney]=='D' || mat[nex][ney]=='T' || dist[nex][ney]!=1e9)return;
dist[nex][ney]=dist[nowx][nowy]+1;
bfs.push({nex,ney});
}
void expand2(int nowx,int nowy,int nex,int ney){
if(nex<0 || nex>=n || ney<0 || ney>=n)return;
if(mat[nex][ney]=='T' || nuedist[nex][ney]!=1e9)return;
int nuevadi=nuedist[nowx][nowy]+1;
//if(nuevadi%s==0)
if(nuevadi/s<=dist[nex][ney]){
nuedist[nex][ney]=nuevadi;
bfs2.push({nex,ney});
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin >> n >> s;
fill(&dist[0][0],&dist[0][0]+800*800,1e9);
for(int i=0;i<n;i++){
for(int j=0;j<n;j++){
cin >> mat[i][j];
if(mat[i][j]=='H'){
dist[i][j]=0;
bfs.push({i,j});
}else if(mat[i][j]=='M'){
mx=i;
my=j;
}else if(mat[i][j]=='D'){
dx=i;
dy=j;
}
}
}
while(!bfs.empty()){
pair<int,int> top=bfs.front();
bfs.pop();
expand(top.first,top.second,top.first+1,top.second);
expand(top.first,top.second,top.first-1,top.second);
expand(top.first,top.second,top.first,top.second+1);
expand(top.first,top.second,top.first,top.second-1);
}
/*for(int i=0;i<n;i++){
for(int j=0;j<n;j++){
cout << dist[i][j] << ' ';
}
cout << endl;
}*/
int l=0,r=dist[mx][my]-1;
while(l<r){
int mid=(l+r+1)>>1;
// comi mid segundos
// puedo ir s bloques por segundo
fill(&nuedist[0][0],&nuedist[0][0]+800*800,1e9);
nuedist[mx][my]=mid*s;
bfs2.push({mx,my});
while(!bfs2.empty()){
pair<int,int> top=bfs2.front();
bfs2.pop();
if(nuedist[top.first][top.second]%s==0 && nuedist[top.first][top.second]/s>=dist[top.first][top.second])continue;
//if(mid==2)cout << top.first << ' ' << top.second << '\n';
expand2(top.first,top.second,top.first+1,top.second);
expand2(top.first,top.second,top.first-1,top.second);
expand2(top.first,top.second,top.first,top.second+1);
expand2(top.first,top.second,top.first,top.second-1);
}
if(nuedist[dx][dy]==1e9)r=mid-1;
else l=mid;
}
cout << l;
}
/*
T T T T T T T
T G G G G G T
T 11 G G G G T
9 10 X X G G D
T X X X X G T
T X X X X X T
T X H H X X T
*/
