#include<bits/stdc++.h>
#define ll long long int
#define pb push_back
#define mp make_pair
#define FOR(i,n) for(i=0;i<(n);++i)
#define FORe(i,n) for(i=1;i<=(n);++i)
#define FORr(i,a,b) for(i=(a);i<(b);++i)
#define FORrev(i,n) for(i=(n);i>=0;--i)
#define F0R(i,n) for(int i=0;i<(n);++i)
#define F0Re(i,n) for(int i=1;i<=(n);++i)
#define F0Rr(i,a,b) for(ll i=(a);i<(b);++i)
#define F0Rrev(i,n) for(int i=(n);i>=0;--i)
#define ii pair<ll,ll>
#define vi vector<ll>
#define vii vector<ii>
#define ff first
#define ss second
#define cd complex<double>
#define vcd vector<cd>
#define ldd long double
#define dbgLine cout<<"Line : "<<__LINE__<<'\n'
#define all(x) (x).begin(),(x).end()
using namespace std;
const short int __PRECISION = 10;
const ll MOD = 1e9+7;
const ll INF = 1e17 + 1101;
const ll LOGN = 17;
const ll MAXN = 2e5+5;
const ll ROOTN = 320;
const int inf = 1e9+2;
const ldd PI = acos(-1);
const ldd EPS = 1e-7;
int N, S, disB[900][900], disM[900][900], X, Y, H, K;
char grid[900][900];
bool vis[900][900];
inline bool inside(int i, int j)
{
return ((i < N) && (i >= 0) && (j < N) && (j >= 0));
}
int main()
{
/*
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
*/
cin>>N>>S;
queue<pair<int, int>> Q;
F0R(i, N)
F0R(j ,N)
{
cin>>grid[i][j];
vis[i][j] = false;
disB[i][j] = inf;
if(grid[i][j] == 'H')
Q.push(mp(i, j)), disB[i][j] = 0, vis[i][j] = true;
else if(grid[i][j] == 'M')
X = i, Y = j;
else if(grid[i][j] == 'D')
H = i, K = j;
}
while(!Q.empty())
{
int x = Q.front().ff, y = Q.front().ss;
Q.pop();
for(pair<int, int> p : {mp(0, -1), mp(0, 1), mp(1, 0), mp(-1, 0)})
if(inside(x+p.ff, y+p.ss) && (!vis[x+p.ff][y+p.ss]) && (grid[x+p.ff][y+p.ss] == 'G' or grid[x+p.ff][y+p.ss] == 'D'))
{
disB[x+p.ff][y+p.ss] = disB[x][y] + 1;
vis[x+p.ff][y+p.ss] = true;
Q.push(mp(x+p.ff, y+p.ss));
}
}
int lo = -1, hi = 4000, mid;
while(lo < hi - 1)
{
mid = (lo + hi)/2;
F0R(i, N)
F0R(j, N)
vis[i][j] = false, disM[i][j] = inf;
vis[X][Y] = true;
disM[X][Y] = 0;
Q.push(mp(X, Y));
while(!Q.empty())
{
int x = Q.front().ff, y = Q.front().ss;
Q.pop();
if ((disM[x][y]%S==0) ? (disB[x][y] <= mid + disM[x][y]/S) : (disB[x][y] < mid + (disM[x][y])/S))
{
disM[x][y] = inf;
continue;
}
for(pair<int, int> p : {mp(0, -1), mp(0, 1), mp(1, 0), mp(-1, 0)})
if(inside(x+p.ff, y+p.ss)&&(!vis[x+p.ff][y+p.ss])&&(grid[x+p.ff][y+p.ss] == 'G' or grid[x+p.ff][y+p.ss] == 'D'))
{
disM[x+p.ff][y+p.ss] = disM[x][y] + 1;
vis[x+p.ff][y+p.ss] = true;
Q.push(mp(x+p.ff, y+p.ss));
}
}
if(disM[H][K] == inf)
hi = mid;
else
lo = mid;
}
cout<<lo;
return 0;
}
