#include <bits/stdc++.h>
using namespace std;
int R, C;
vector <vector <char>> s;
vector <vector <int>> fenwick;
void update(int x, int y, int v) {
for(int i = x; i <= R; i += (i & -i)) {
for(int j = y; j <= C; j += (j & -j)) {
fenwick[i][j] += v;
}
}
}
int query(int x, int y) {
int res = 0;
for(int i = x; i >= 1; i -= (i & -i)) {
for(int j = y; j >= 1; j -= (j & -j)) {
res += fenwick[i][j];
}
}
return res;
}
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int D, K;
cin >> R >> C >> D >> K;
s.resize(R + 10, vector <char> (C + 10));
for(int i = 1; i <= R; i++) {
for(int j = 1; j <= C; j++) {
cin >> s[i][j];
}
}
fenwick.resize(R + 10, vector <int> (C + 10, 0));
for(int i = 1; i <= R; i++) {
for(int j = 1; j <= C; j++) {
if(s[i][j] == 'S') {
int minx = max(1, i - D), miny = max(1, j - D);
int maxx = min(R, i + D), maxy = min(C, j + D);
update(minx, miny, 1);
update(minx, maxy + 1, -1);
update(maxx + 1, miny, -1);
update(maxx + 1, maxy + 1, 1);
}
}
}
int ans = 0;
for(int i = 1; i <= R; i++) {
for(int j = 1; j <= C; j++) {
if(s[i][j] == 'M' and query(i, j) >= K) {
ans++;
}
}
}
cout << ans;
return 0;
}
