// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>
using namespace std;
#define nl '\n'
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define sz(x) int(x.size())
template<class T> using V = vector<T>;
using vi = V<int>;
using ll = long long;
using pi = pair<int, int>;
using vpi = V<pi>;
using vl = V<ll>;
using db = double;
const int INF = 1e9 + 10;
int main() {
cin.tie(0)->sync_with_stdio(0);
int N, M, D, K; cin >> N >> M >> D >> K;
V<string> A(N); for(auto& x : A) cin >> x;
V<vi> P(N + 1, vi(M + 1));
for(int r = 0; r < N; r++) {
for(int c = 0; c < M; c++) if (A[r][c] == 'S') {
int tr = max(0, r - D), tc = max(0, c - D);
int br = min(N - 1, r + D) + 1, bc = min(M - 1, c + D) + 1;
P[tr][tc]++;
P[tr][bc]--;
P[br][tc]--;
P[br][bc]++;
}
}
int ans = 0;
for(int r = 0; r < N; r++) {
for(int c = 0; c < M; c++) {
if (r) P[r][c] += P[r-1][c];
if (c) P[r][c] += P[r][c-1];
if (r && c) P[r][c] -= P[r-1][c-1];
if (A[r][c] == 'M') ans += (P[r][c] >= K);
}
}
cout << ans << nl;
exit(0-0);
}
