#include <bits/stdc++.h>
#define ll long long
#define KAGAMINE ios_base::sync_with_stdio(false);
#define LEN cin.tie(NULL);
#define pls cout << "mantap\n";
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define pb push_back
#define vector2d(x) vector<vector<x>>
#define pii pair<int, int>
#define pl pair<ll, ll>
using namespace std;
int r, c, d, k;
vector<pii> mus, spr;
int addsum(vector2d(int)& pf, int r1, int c1, int r2, int c2){
int dec1 = 0, dec2 = 0, inc = 0;
if (r1 > 0) dec1 = pf[r1-1][c2];
if (c1 > 0) dec2 = pf[r2][c1-1];
if (r1 > 0 && c1 > 0) inc = pf[r1-1][c1-1];
return pf[r2][c2] - dec1 - dec2 + inc;
}
void fin(){
vector2d(int) pf(r, vector<int>(c, 0));
for (auto [rs, cs] : spr){
pf[rs][cs] = 1;
}
for (int i = 0; i < r; i++){
for (int j = 0; j < c; j++){
if (i > 0) pf[i][j] += pf[i-1][j];
if (j > 0) pf[i][j] += pf[i][j-1];
if (i > 0 && j > 0) pf[i][j] -= pf[i-1][j-1];
}
}
int ans = 0;
for (auto [mr, mc] : mus){
if (addsum(pf, max(0,mr-d), max(0,mc-d), min(r-1,mr+d), min(c-1,mc+d)) >= k){
ans++;
}
}
cout << ans;
}
int main(){
KAGAMINE LEN
cin >> r >> c >> d >> k;
for (int i = 0; i < r; i++){
for (int j = 0; j < c; j++){
char tmp; cin >> tmp;
if (tmp == 'S') spr.pb({i,j});
if (tmp == 'M') mus.pb({i,j});
}
}
fin();
// sub3();
return 0;
}
