#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n,m,d,k;
cin >> n >> m >> d >> k;
vector<vector<char>> c(n + 1,vector<char>(m + 1));
for(int i = 1;i <= n;i++){
for(int j = 1;j <= m;j++){
cin >> c[i][j];
}
}
vector<vector<int>> a(n + 1,vector<int>(m + 1));
vector<vector<int>> pref(n + 1, vector<int>(m + 1));
for(int i = 1;i <= n;i++){
for(int j = 1;j <= m;j++){
if(c[i][j] == 'S'){
a[i][j] = 1;
}
}
}
for (int i = 1;i <= n;i++) {
for (int j = 1;j <= m;j++) {
pref[i][j] = a[i][j] + pref[i - 1][j] + pref[i][j - 1] - pref[i - 1][j - 1];
}
}
/*
1 2 3 4 5
6 7 8 9 1
1 2 3 4 5
1 2 3 4 5
*/
int ans = 0;
for(int i = 1;i <= n;i++){
for(int j = 1;j <= m;j++){
if(c[i][j] != 'M') continue;
int x1 = max(1,i - d);
int x2 = min(n,i + d);
int y1 = max(1,j - d);
int y2 = min(m,j + d);
int tot = pref[x2][y2] - pref[x1 - 1][y2] - pref[x2][y1 - 1] + pref[x1 - 1][y1 - 1];
if(tot >= k){
ans ++;
}
}
}
cout << ans << '\n';
return 0;
}
