#include <bits/stdc++.h>
using namespace std;
template <typename T>
T inverse(T a, T m) {
T u = 0, v = 1;
while (a != 0) {
T t = m / a;
m -= t * a; swap(a, m);
u -= t * v; swap(u, v);
}
assert(m == 1);
return u;
}
template <typename T>
class Modular {
public:
using Type = typename decay<decltype(T::value)>::type;
constexpr Modular() : value() {}
template <typename U>
Modular(const U& x) {
value = normalize(x);
}
template <typename U>
static Type normalize(const U& x) {
Type v;
if (-mod() <= x && x < mod()) v = static_cast<Type>(x);
else v = static_cast<Type>(x % mod());
if (v < 0) v += mod();
return v;
}
const Type& operator()() const { return value; }
template <typename U>
explicit operator U() const { return static_cast<U>(value); }
constexpr static Type mod() { return T::value; }
Modular& operator+=(const Modular& other) { if ((value += other.value) >= mod()) value -= mod(); return *this; }
Modular& operator-=(const Modular& other) { if ((value -= other.value) < 0) value += mod(); return *this; }
template <typename U> Modular& operator+=(const U& other) { return *this += Modular(other); }
template <typename U> Modular& operator-=(const U& other) { return *this -= Modular(other); }
Modular& operator++() { return *this += 1; }
Modular& operator--() { return *this -= 1; }
Modular operator++(int) { Modular result(*this); *this += 1; return result; }
Modular operator--(int) { Modular result(*this); *this -= 1; return result; }
Modular operator-() const { return Modular(-value); }
template <typename U = T>
typename enable_if<is_same<typename Modular<U>::Type, int>::value, Modular>::type& operator*=(const Modular& rhs) {
#ifdef _WIN32
uint64_t x = static_cast<int64_t>(value) * static_cast<int64_t>(rhs.value);
uint32_t xh = static_cast<uint32_t>(x >> 32), xl = static_cast<uint32_t>(x), d, m;
asm(
"divl %4; \n\t"
: "=a" (d), "=d" (m)
: "d" (xh), "a" (xl), "r" (mod())
);
value = m;
#else
value = normalize(static_cast<int64_t>(value) * static_cast<int64_t>(rhs.value));
#endif
return *this;
}
template <typename U = T>
typename enable_if<is_same<typename Modular<U>::Type, int64_t>::value, Modular>::type& operator*=(const Modular& rhs) {
int64_t q = static_cast<int64_t>(static_cast<long double>(value) * rhs.value / mod());
value = normalize(value * rhs.value - q * mod());
return *this;
}
template <typename U = T>
typename enable_if<!is_integral<typename Modular<U>::Type>::value, Modular>::type& operator*=(const Modular& rhs) {
value = normalize(value * rhs.value);
return *this;
}
Modular& operator/=(const Modular& other) { return *this *= Modular(inverse(other.value, mod())); }
template <typename U>
friend const Modular<U>& abs(const Modular<U>& v) { return v; }
template <typename U>
friend bool operator==(const Modular<U>& lhs, const Modular<U>& rhs);
template <typename U>
friend bool operator<(const Modular<U>& lhs, const Modular<U>& rhs);
template <typename U>
friend std::istream& operator>>(std::istream& stream, Modular<U>& number);
private:
Type value;
};
template <typename T> bool operator==(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value == rhs.value; }
template <typename T, typename U> bool operator==(const Modular<T>& lhs, U rhs) { return lhs == Modular<T>(rhs); }
template <typename T, typename U> bool operator==(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) == rhs; }
template <typename T> bool operator!=(const Modular<T>& lhs, const Modular<T>& rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(const Modular<T>& lhs, U rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(U lhs, const Modular<T>& rhs) { return !(lhs == rhs); }
template <typename T> bool operator<(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value < rhs.value; }
template <typename T> Modular<T> operator+(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }
template <typename T> Modular<T> operator-(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T> Modular<T> operator*(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T> Modular<T> operator/(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }
template<typename T, typename U>
Modular<T> power(const Modular<T>& a, const U& b) {
assert(b >= 0);
Modular<T> x = a, res = 1;
U p = b;
while (p > 0) {
if (p & 1) res *= x;
x *= x;
p >>= 1;
}
return res;
}
template <typename T>
bool IsZero(const Modular<T>& number) {
return number() == 0;
}
template <typename T>
string to_string(const Modular<T>& number) {
return to_string(number());
}
template <typename T>
std::ostream& operator<<(std::ostream& stream, const Modular<T>& number) {
return stream << number();
}
template <typename T>
std::istream& operator>>(std::istream& stream, Modular<T>& number) {
typename common_type<typename Modular<T>::Type, int64_t>::type x;
stream >> x;
number.value = Modular<T>::normalize(x);
return stream;
}
using ll = long long;
using vi = vector<int>;
#define pb push_back
#define all(x) begin(x), end(x)
#define sz(x) (int) (x).size()
#define ite(x,n) for (int i = x; i<n; i++);
using pii = pair<int,int>;
#define fr first
#define sc second
#define mp make_pair
void setIO(string name = "") {
cin.tie(0)->sync_with_stdio(0); // see /general/fast-io
if (sz(name)) {
freopen((name + ".in").c_str(), "r", stdin); // see /general/input-output
freopen((name + ".out").c_str(), "w", stdout);
}
}
int inf = (int)1e6 + 1;
int MOD = 1e9 + 7;
int dx[4] = {1,-1,0,0};
int dy[4] = {0,0,1,-1};
int MAX_VAL = 50;
int main(){
setIO("");
int n, s;
cin >> n >> s;
char grid[n + 1][n + 1];
pii mecho, destination;
queue<pii>q;
int bees[n + 1][n + 1], dist[n + 1][n + 1];
for (int i = 1; i<=n; i++){
for (int j = 1; j<=n; j++){
cin >> grid[i][j];
bees[i][j] = -1;
dist[i][j] = -1;
if (grid[i][j] == 'M'){
mecho = mp(i,j);
dist[i][j]=0;
}else if (grid[i][j] == 'D'){
destination = mp(i,j);
}else if (grid[i][j] == 'H'){
//hive
bees[i][j]=0;
q.push(mp(i,j));
}
}
}
while(!q.empty()){
pii node = q.front();
q.pop();
//cout<<node.fr<<" "<<node.sc<<" "<<bees[node.fr][node.sc]<<endl;
for(int i = 0; i<4; i++){
pii nxt = {node.fr + dx[i], node.sc + dy[i]};
if (nxt.fr <= n && nxt.fr >= 1 && nxt.sc <= n && nxt.sc >= 1 && (grid[nxt.fr][nxt.sc] =='G' ||grid[nxt.fr][nxt.sc] =='M') && bees[nxt.fr][nxt.sc] == -1){
bees[nxt.fr][nxt.sc] = 1 + bees[node.fr][node.sc];
q.push(nxt);
}
}
}
int ans = -1;
int l = 0;
int r = n*n;
while(l<=r){
int mid = (l + r)/2;
//mid minuti sme jadele
if (bees[mecho.fr][mecho.sc] <= mid){
r = mid - 1;
continue;
}
queue<pair<int,pii>>qq;
memset(dist, -1, sizeof(dist));
dist[mecho.fr][mecho.sc] = mid;
qq.push(mp(0, mecho));
while(!qq.empty()){
int streak = qq.front().fr;
pii node = qq.front().sc;
//cout<<node.fr<<" "<<node.sc<<" "<<dist[node.fr][node.sc]<<endl;
qq.pop();
for (int i = 0; i<4; i++){
pii nxt = {node.fr + dx[i], node.sc + dy[i]};
if (nxt.fr <= n && nxt.fr >= 1 && nxt.sc <= n && nxt.sc >= 1 && grid[nxt.fr][nxt.sc] !='T' && grid[nxt.fr][nxt.sc] !='H' && dist[nxt.fr][nxt.sc] == -1){
int new_dist = dist[node.fr][node.sc] + (streak + 1 == s);
if (new_dist < bees[nxt.fr][nxt.sc] || bees[nxt.fr][nxt.sc] == -1){
dist[nxt.fr][nxt.sc] = new_dist;
int ns = streak + 1;
if (ns == s)ns = 0;
qq.push(mp(ns, nxt));
}
}
}
}
if (dist[destination.fr][destination.sc] > -1){
ans = mid;
l = mid + 1;
}else{
r = mid - 1;
}
}
cout<<ans;
return 0;
}
