#include <bits/stdc++.h>
using namespace std;
int n, m, d, k;
vector <vector <int> > f;
vector <vector <char> > a;
int main(){
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> n >> m >> d >> k;
a.assign(n + 5, vector <char>(m + 5, '#')); f.assign(n + 5, vector <int>(m + 5, 0));
for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) cin >> a[i][j];
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
if (a[i][j] == 'S') {
int x = i - d, y = j - d, x2 = i + d, y2 = j + d;
x = max(x, 1); y = max(y, 1); x2 = min(x2, n); y2 = min(y2, m);
f[x][y]++; f[x2 + 1][y]--; f[x][y2 + 1]--; f[x2 + 1][y2 + 1]++;
}
}
}
for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) f[i][j] += f[i - 1][j] + f[i][j - 1] - f[i - 1][j - 1];
int ans = 0;
for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) if (a[i][j] == 'M' && f[i][j] >= k) ans++;
cout << ans;
return 0;
}
