#pragma GCC optimize("O3", "inline")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#define pb push_back
#define ub upper_bound
const ll INF = 1e18 + 100;
vector<int> ra = {-1, 0, 1, 0};
vector<int> ca = {0, 1, 0, -1};
int f(int n, vector<string> &a, int s, int m, vector<int> &sp, vector<int> &ep)
{
if (sp[0] == ep[0] && sp[1] == ep[1])
return 1;
queue<pair<int, int>> q1;
vector<vector<int>> v(n, vector<int>(n, 0));
v[ep[0]][ep[1]] = 1;
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
{
if (a[i][j] == 'H')
{
q1.push({i, j});
v[i][j] = 1;
}
else if (a[i][j] == 'T')
v[i][j] = 1;
}
for (int i = 0; i < m; i++)
{
int sz = q1.size();
while (sz-- > 0)
{
auto del = q1.front();
q1.pop();
for (int d = 0; d < 4; d++)
{
int nr = del.first + ra[d], nc = del.second + ca[d];
if (nr >= 0 && nr < n && nc >= 0 && nc < n && v[nr][nc] == 0)
{
q1.push({nr, nc});
v[nr][nc] = 1;
}
}
}
}
if (v[sp[0]][sp[1]] == 1)
return 0;
queue<pair<int, int>> q2;
q2.push({sp[0], sp[1]});
v[sp[0]][sp[1]] = 2;
while (q2.size())
{
int sz;
for (int i = 0; i < s; i++)
{
sz = q2.size();
while (sz-- > 0)
{
auto del = q2.front();
q2.pop();
if (v[del.first][del.second] == 1)
continue;
for (int d = 0; d < 4; d++)
{
int nr = del.first + ra[d], nc = del.second + ca[d];
if (nr >= 0 && nr < n && nc >= 0 && nc < n)
{
if (nr == ep[0] && nc == ep[1])
return 1;
if (v[nr][nc] == 0)
{
q2.push({nr, nc});
v[nr][nc] = 2;
}
}
}
}
}
sz = q1.size();
while (sz-- > 0)
{
auto del = q1.front();
q1.pop();
for (int d = 0; d < 4; d++)
{
int nr = del.first + ra[d], nc = del.second + ca[d];
if (nr >= 0 && nr < n && nc >= 0 && nc < n && v[nr][nc] != 1)
{
q1.push({nr, nc});
v[nr][nc] = 1;
}
}
}
}
return 0;
}
ll solve()
{
int n, s;
cin >> n >> s;
vector<string> a(n);
for (int i = 0; i < n; i++)
cin >> a[i];
vector<int> sp(2), ep(2);
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
{
if (a[i][j] == 'M')
sp = {i, j};
if (a[i][j] == 'D')
ep = {i, j};
}
int l = 0, h = 2 * n, ma = -1;
while (l <= h)
{
int m = (l + h) / 2;
if (f(n, a, s, m, sp, ep))
{
ma = m;
l = m + 1;
}
else
h = m - 1;
}
return ma;
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int t = 1;
while (t--)
{
ll x = solve();
cout << x << "\n";
}
return 0;
}
