#include <bits/stdc++.h>
using namespace std;
const int mxN=800;
int n, s, d1[mxN][mxN], d2[mxN][mxN], si, sj, ti, tj, lb=0, rb=mxN*mxN, nb[4][2]={{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
string g[mxN];
array<int, 2> qu[mxN*mxN];
void bfs(int d[mxN][mxN], int a) {
int qt=0;
for(int i=0; i<n; ++i)
for(int j=0; j<n; ++j)
if(!d[i][j])
qu[qt++]={i, j};
for(int i=0; i<qt; ++i) {
array<int, 2> u=qu[i];
// if(a)
// cout << u[0] << " " << u[1] << endl;
if(a>=0&&d[u[0]][u[1]]/s+a>=d1[u[0]][u[1]])
continue;
for(int j=0; j<4; ++j) {
int ni=u[0]+nb[j][0], nj=u[1]+nb[j][1];
if(ni>=0&&ni<n&&nj>=0&&nj<n&&g[ni][nj]!='T'&&(a>=0||g[ni][nj]!='D')&&d[ni][nj]>1e7) {
d[ni][nj]=d[u[0]][u[1]]+1;
qu[qt++]={ni, nj};
}
}
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> s;
for(int i=0; i<n; ++i)
cin >> g[i];
memset(d1, 1, sizeof(d1));
for(int i=0; i<n; ++i) {
for(int j=0; j<n; ++j) {
if(g[i][j]=='M') {
si=i;
sj=j;
} else if(g[i][j]=='D') {
ti=i;
tj=j;
} else if(g[i][j]=='H')
d1[i][j]=0;
}
}
bfs(d1, -1);
while(lb<=rb) {
int mb=(lb+rb)/2;
// cout << "bs " << mb << endl;
memset(d2, 1, sizeof(d2));
d2[si][sj]=0;
bfs(d2, mb);
if(d2[ti][tj]<1e7)
lb=mb+1;
else
rb=mb-1;
}
cout << rb;
}
