#include <bits/stdc++.h>
#define DEBUG 0
using namespace std;
vector <vector <char>> a;
class Fenwick {
protected :
int R, C;
vector <vector <int>> fenwick;
public :
Fenwick(int r, int c) : R(r), C(c) {
fenwick.resize(r + 10, vector <int> (c + 10, 0));
}
int lsb(int x) {
return x & -x;
}
void update(int x, int y, int val) {
for(; x <= R; x += lsb(x)) {
for(int idx = y; idx <= C; idx += lsb(idx)) {
fenwick[x][idx] += val;
}
}
}
int query(int x, int y) {
int res = 0;
for(; x > 0; x -= lsb(x)) {
for(int idx = y; idx > 0; idx -= lsb(idx)) {
res += fenwick[x][idx];
}
}
return res;
}
};
int main() {
int R, C, D, K;
scanf(" %d %d %d %d", &R, &C, &D, &K);
a.resize(R + 10, vector <char> (C + 10));
for(int i = 1; i <= R; i++) {
for(int j = 1; j <= C; j++) {
scanf(" %c", &a[i][j]);
}
}
Fenwick fw(R, C);
for(int i = 1; i <= R; i++) {
for(int j = 1; j <= C; j++) {
if(a[i][j] == 'S') {
int min_x = max(1, i - D), max_x = min(R + 1, i + D + 1);
int min_y = max(1, j - D), max_y = min(C + 1, j + D + 1);
fw.update(min_x, min_y, 1);
fw.update(max_x, min_y, -1);
fw.update(min_x, max_y, -1);
fw.update(max_x, max_y, 1);
}
}
}
if(DEBUG) {
cout << "Debugging :\n";
for(int i = 1; i <= R; i++) {
for(int j = 1; j <= C; j++) {
cout << fw.query(i, j) << " ";
}
cout << endl;
}
}
int ans = 0;
for(int i = 1; i <= R; i++) {
for(int j = 1; j <= C; j++) {
if(a[i][j] == 'M' and fw.query(i, j) >= K) {
ans++;
}
}
}
cout << ans;
return 0;
}
