#include <bits/stdc++.h>
#define int long long
using namespace std;
char arr[801][801];
int n, s;
int stx, sty, ex, ey;
bool in(int x, int y)
{
return (min(x, y) >= 1 && max(x, y) <= n);
}
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, 1, 0, -1};
int dBee[801][801];
int D[801][801];
bool check(int mid)
{
memset(D, 0x3f, sizeof D);
D[stx][sty] = mid * s;
queue<pair<int, int>> q;
q.emplace(stx, sty);
while (!q.empty())
{
int ux, uy;
tie(ux, uy) = q.front();
q.pop();
if (D[ux][uy] >= dBee[ux][uy]) continue;
for (int i = 0; i < 4; i++)
{
int vx = ux + dx[i];
int vy = uy + dy[i];
if (in(vx, vy) && arr[vx][vy] != 'T' && D[vx][vy] > D[ux][uy] + 1)
{
D[vx][vy] = D[ux][uy] + 1;
q.emplace(vx, vy);
}
}
}
if (D[ex][ey] < (int)1e18) return true;
else return false;
}
int32_t main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
//freopen("TEST.IN", "r", stdin);
//freopen("TEST.OUT", "w", stdout);
cin >> n >> s;
queue<pair<int, int>> q;
memset(dBee, 0x3f, sizeof dBee);
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= n; j++)
{
cin >> arr[i][j];
if (arr[i][j] == 'H')
{
q.emplace(i, j);
dBee[i][j] = 0;
}
if (arr[i][j] == 'M')
{
tie(stx, sty) = make_pair(i, j);
}
if (arr[i][j] == 'D')
{
tie(ex, ey) = make_pair(i, j);
}
}
}
while (!q.empty())
{
int ux, uy;
tie(ux, uy) = q.front();
q.pop();
for (int i = 0; i < 4; i++)
{
int vx = ux + dx[i];
int vy = uy + dy[i];
if (in(vx, vy) && arr[vx][vy] != 'D' && dBee[vx][vy] > dBee[ux][uy] + s)
{
dBee[vx][vy] = dBee[ux][uy] + s;
q.emplace(vx, vy);
}
}
}
int l = 0;
int r = 1e9;
int ans = -1;
while (l <= r)
{
int mid = (l + r) / 2;
if (check(mid))
{
ans = mid;
l = mid + 1;
}
else r = mid - 1;
}
cout << ans;
return 0;
}
