#include <bits/stdc++.h>
using namespace std;
int main() {
int r, c, d, k; cin >> r >> c >> d >> k;
vector<vector<char>> grid(r, vector<char> (c));
vector<vector<int>> ps(r+1, vector<int> (c+1));
for (int i = 0; i < r; ++i) {
string s; cin >> s;
for (int j = 0; j < c; ++j) {
grid[i][j] = s[j];
ps[i+1][j+1] = (grid[i][j] == 'S' ? 1 : 0);
}
}
for (int i = 1; i <= r; ++i) {
for (int j = 1; j <= c; ++j) {
ps[i][j] += ps[i][j-1]+ps[i-1][j]-ps[i-1][j-1];
}
}
int a = 0;
for (int i = 0; i < r; ++i) {
for (int j = 0; j < c; ++j) {
if (grid[i][j] == 'M') {
int x1 = max(0, i-d);
int x2 = min(r-1, i+d);
int y1 = max(0, j-d);
int y2 = min(c-1, j+d);
int sum = ps[x2+1][y2+1]+ps[x1][y1]-ps[x1][y2+1]-ps[x2+1][y1];
if (sum >= k) a++;
}
}
}
cout << a;
}
