#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
int r, c, d, k;
cin >> r >> c >> d >> k;
char ch[r][c];
int p[r + 1][c + 1] ={0};
vector<pair<int, int>> muug;
for (int i = 0; i < r; i++) {
for (int j = 0; j < c; j++) {
cin >> ch[i][j];
if(ch[i][j] == 'M') {
muug.push_back({i, j});
}
else if(ch[i][j] == 'S') {
p[i + 1][j + 1] = 1;
}
}
}
for (int i = 1; i <= r; i++) {
for (int j = 1; j <= c; j++) {
p[i][j] += p[i - 1][j] + p[i][j- 1] - p[i - 1][j - 1];
}
}
int ans = 0;
for(pair<int, int> pr : muug){
int x=pr.first, y=pr.second;
int x1 = max(0LL, x - d) + 1;
int y1 = max(0LL, y - d) + 1;
int x2 = min(r - 1, x + d) + 1;
int y2 = min(c - 1, y + d) + 1;
int cnt = p[x2][y2] - p[x1-1][y2] - p[x2][y1-1] + p[x1-1][y1-1];
if (cnt >= k) ans++;
}
cout << ans;
}
