#pragma GCC optimize("-O3")
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define vl vector<ll>
#define vi vector<int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pb push_back
#define p_b pop_back
#define f first
#define s second
using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
const ll sz = 850;
char grid[sz][sz];
ll dist[sz][sz], ch[sz][sz], n, s, i, j, k;
ll dx[] = {0, 1, 0, -1};
ll dy[] = {1, 0, -1, 0};
pll st, en;
ll bfs(ll mid)
{
if(dist[st.f][st.s] - mid * s <= 0)
return 0;
for(i = 1; i <= n; i++)
{
for(j = 1; j <= n; j++)
ch[i][j] = 0;
}
queue<pll>q;
q.push(st);
while(!q.empty())
{
pll node = q.front();
q.pop();
for(k = 0; k < 4; k++)
{
pll nnode = {node.f + dx[k], node.s + dy[k]};
if(nnode.f >= 1 && nnode.f <= n && nnode.s >= 1 && nnode.s <= n)
{
if(ch[nnode.f][nnode.s] == 0 && grid[nnode.f][nnode.s] != 'T' && grid[nnode.f][nnode.s] != 'M' && dist[nnode.f][nnode.s] - mid * s > ch[node.f][node.s] + 1)
{
ch[nnode.f][nnode.s] = ch[node.f][node.s] + 1;
q.push(nnode);
}
}
}
}
if(ch[en.f][en.s] > 0)
return 1;
return 0;
}
void solve()
{
cin >> n >> s;
queue<pll>q;
for(i = 1; i <= n; i++)
{
for(j = 1; j <= n; j++){
cin >> grid[i][j];
if(grid[i][j] == 'M')
st = {i, j};
else if(grid[i][j] == 'D')
en = {i, j};
else if(grid[i][j] == 'H')
q.push({i, j});
}
}
while(!q.empty())
{
pll node = q.front();
q.pop();
for(k = 0; k < 4; k++)
{
pll nnode = {node.f + dx[k], node.s + dy[k]};
if(nnode.f >= 1 && nnode.f <= n && nnode.s >= 1 && nnode.s <= n)
{
if(dist[nnode.f][nnode.s] == 0 && grid[nnode.f][nnode.s] != 'H' && grid[nnode.f][nnode.s] != 'T' && grid[nnode.f][nnode.s] != 'D')
{
dist[nnode.f][nnode.s] = dist[node.f][node.s] + s;
q.push(nnode);
}
}
}
}
dist[en.f][en.s] = LLONG_MAX;
ll l = 0, r = 1000000000, ans = -1;
while(l <= r)
{
ll mid = (l + r) / 2;
if(bfs(mid))
{
ans = max(ans, mid);
l = mid + 1;
}
else
r = mid - 1;
}
cout << ans << "\n";
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
ll tests = 1;
//cin >> tests;
while(tests--)
{
solve();
}
}
