#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define pii pair<int, int>
#define all(a) a.begin(), a.end()
using namespace std;
#ifdef LOCAL
#include "C:\Users\Dell\Downloads\template\template\icpc-notebook\Utilities\debug.h"
#else
#define debug(...) 42
#endif
const int mn = 5e5 + 5, mod = 1e9 + 7, inf = 2e9;
int r, c, d, k;
vector<vector<char>> a;
vector<vector<int>> bit;
void add(int x, int y, int val){
for(int i = x; i <= r; i += i & -i){
for(int j = y; j <= c; j += j & -j){
bit[i][j] += val;
}
}
}
int get(int x, int y){
int r = 0;
for(int i = x; i; i -= i & -i){
for(int j = y; j; j -= j & -j){
r += bit[i][j];
}
}
return r;
}
void solve() {
cin >> r >> c >> d >> k;
a.resize(r + 5, vector <char> (c + 5));
bit.resize(r + 5, vector <int> (c + 5));
for(int i = 1; i <= r; i++){
for(int j = 1; j <= c; j++){
cin >> a[i][j];
if(a[i][j] == 'S'){
int x1 = max(i - d, 1);
int y1 = max(j - d, 1);
int x2 = min(i + d, r);
int y2 = min(j + d, c);
debug(x1, y1, x2, y2);
add(x1, y1, 1);
add(x1, y2 + 1, -1);
add(x2 + 1, y1, -1);
add(x2 + 1, y2 + 1, 1);
}
}
}
int res = 0;
for(int i = 1; i <= r; i++){
for(int j = 1; j <= c; j++){
if(a[i][j] == 'M'){
int val = get(i, j);
res += (val >= k);
}
}
}
cout << res << '\n';
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
#define task "Kawabata"
if (fopen(task".INP", "r")) {
freopen(task".INP", "r", stdin);
freopen(task".OUT", "w", stdout);
}
int t = 1;
// cin >> t;
while (t--) solve();
return 0;
}
// Don't wanna lose anymore T_T
// Never let me go - Kazuo Ishiguro
