#include <stdio.h>
#define N 800
int di[] = { -1, 1, 0, 0 };
int dj[] = { 0, 0, -1, 1 };
char cc[N][N + 1];
int dd_[N][N], dd[N][N], qu[N * N], n, s;
int solve(int im, int jm, int id, int jd, int t) {
int i, j, head, cnt;
for (i = 0; i < n; i++)
for (j = 0; j < n; j++)
dd[i][j] = n * n;
head = cnt = 0;
dd[im][jm] = 0, qu[head + cnt++] = im * n + jm;
while (cnt) {
int ij, h, d;
ij = qu[cnt--, head++], i = ij / n, j = ij % n, d = dd[i][j] + 1;
if (dd_[i][j] <= t + dd[i][j] / s)
continue;
if (i == id && j == jd)
return 1;
for (h = 0; h < 4; h++) {
int i_ = i + di[h], j_ = j + dj[h];
if (i_ >= 0 && i_ < n && j_ >= 0 && j_ < n && cc[i_][j_] != 'T' && dd[i_][j_] > d)
dd[i_][j_] = d, qu[head + cnt++] = i_ * n + j_;
}
}
return 0;
}
int main() {
int i, j, im, jm, id, jd, head, cnt, lower, upper;
scanf("%d%d", &n, &s);
for (i = 0; i < n; i++)
scanf("%s", cc[i]);
head = cnt = 0;
im = jm = id = jd = -1;
for (i = 0; i < n; i++)
for (j = 0; j < n; j++) {
if (cc[i][j] == 'H')
dd_[i][j] = 0, qu[head + cnt++] = i * n + j;
else
dd_[i][j] = n * n;
if (cc[i][j] == 'M')
im = i, jm = j;
else if (cc[i][j] == 'D')
id = i, jd = j;
}
while (cnt) {
int ij, d, h;
ij = qu[cnt--, head++], i = ij / n, j = ij % n, d = dd_[i][j] + 1;
for (h = 0; h < 4; h++) {
int i_ = i + di[h], j_ = j + dj[h];
if (i_ >= 0 && i_ < n && j_ >= 0 && j_ < n && (cc[i_][j_] == 'G' || cc[i_][j_] == 'M') && dd_[i_][j_] > d)
dd_[i_][j_] = d, qu[head + cnt++] = i_ * n + j_;
}
}
lower = -1, upper = n * n + 1;
while (upper - lower > 1) {
int t = (lower + upper) / 2;
if (solve(im, jm, id, jd, t))
lower = t;
else
upper = t;
}
printf("%d\n", lower);
return 0;
}
