// Calm down.
// Think three times, code twice.
#include "bits/stdc++.h"
#define forr(_a,_b,_c) for(int _a = (_b); _a <= (_c); ++_a)
#define ford(_a,_b,_c) for(int _a = (_b) + 1; _a --> (_c);)
#define forf(_a,_b,_c) for(int _a = (_b); _a < (_c); ++_a)
#define st first
#define nd second
#define ll long long
#define ull unsigned long long
#define pii pair <ll,ll>
#define pll pair <ll,ll>
#define piii pair <ll,pii>
#define vi vector <int>
#define pb push_back
#define mp make_pair
#define all(x) begin(x),end(x)
#define mask(i) (1LL << (i))
#define bit(x, i) (((x) >> (i)) & 1)
#define bp __builtin_popcountll
#define file "test"
using namespace std;
const int N = 2e5 + 5;
const int mod = 1e9 + 7; // 998244353
const ll oo = 1e18;
pii bd, en;
ll n, s, dx[] {1, -1, 0, 0}, dy[] {0, 0, 1, -1}, d[1005][1005], d1[1005][1005];
char a[1005][1005];
queue<piii> q;
bool check(ll x, ll y) {
if(x > n || x < 1 || y > n || y < 1 || a[x][y] == 'T') return false;
return true;
}
bool kt(ll mid) {
if(mid >= d[bd.st][bd.nd]) return false;
memset(d1, 0, sizeof d1);
q.push({mid * s, {bd.st, bd.nd}});
while(q.size()) {
ll dxy = q.front().st, x = q.front().nd.st, y = q.front().nd.nd; q.pop();
if(d1[x][y]) continue;
d1[x][y] = 1;
forr(i, 0, 3) {
ll nx = x + dx[i], ny = y + dy[i];
if(!check(nx, ny)) continue;
if((dxy + 1) / s < d[nx][ny]) {
// cout << nx << " " << ny << " " << dxy + 1 << " " << d[nx][ny] << " " << (dxy + 1) / s + ((dxy + 1) % s != 0) << "\n";
q.push({dxy + 1, {nx, ny}});
}
}
}
return d1[en.st][en.nd];
}
void to_nho_cau() {
cin >> n >> s;
memset(d, 63, sizeof d);
forr(i, 1, n) {
forr(j, 1, n) {
cin >> a[i][j];
if(a[i][j] == 'H') {
d[i][j] = 0;
q.push({0, {i, j}});
}
if(a[i][j] == 'M') bd = {i, j};
if(a[i][j] == 'D') en = {i, j};
}
}
while(q.size()) {
ll dxy = q.front().st, x = q.front().nd.st, y = q.front().nd.nd; q.pop();
if(d[x][y] < dxy) continue;
forr(i, 0, 3) {
ll nx = x + dx[i], ny = y + dy[i];
if(!check(nx, ny) || a[nx][ny] == 'D') continue;
if(dxy + 1 < d[nx][ny]) {
d[nx][ny] = dxy + 1;
q.push({dxy + 1, {nx, ny}});
}
}
}
ll l = 0, r = mod, ans = -1;
while(l <= r) {
ll mid = (l + r) >> 1;
if(kt(mid)) {
ans = mid;
l = mid + 1;
} else r = mid - 1;
}
cout << ans << "\n";
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);
// #ifdef LOCAL
//freopen(file".inp","r",stdin);
//freopen(file".out","w",stdout);
// #endif
int t = 1;
//cin >> t;
while(t--) to_nho_cau();
}
