#include <bits/stdc++.h>
using namespace std;
#define int long long
const int inf = 1e17, mod = 998244353, N = 5e6+5;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define rnd(l, r) uniform_int_distribution<int>(l, r)(rng)
int bp (int a, int n, int md) {
int res = 1, p = a;
while(n > 0) {
if(n & 1) res = res * p % md;
p = p * p % md;
n >>= 1;
};
return res;
};
int gcd(int a, int b, int & x1, int & y1) {
if(b == 0) {
x1 = 1;
y1 = 0;
return a;
};
int x = 0, y = 0;
int g = gcd(b, a%b, y, x);
// b * y + a % b * x = g
// b * y + a * x - b * (a/b)*x = g
// a * x + b * (y - (a/b)*x) = g
x1 = x;
y1 = y - (a/b) * x;
return g;
};
void solve() {
int n, m, d, k;
cin >> n >> m >> d >> k;
vector<string> s(n);
for(auto&i : s) cin >> i;
vector<vector<int>> p(n+2, vector<int> (m+2));
for(int i = 1; i <= n; i ++ ) {
for(int j = 1; j <= m; j ++ ) {
if(s[i-1][j-1] != 'S')continue;
int x = i-d, y = j-d;
x = max(x, 1ll);y = max(y, 1ll);
int x1 = i+d+1, y1 = j+d+1;
x1 = min(x1, n+1); y1 = min(y1, m+1);
p[x][y] ++;
p[x1][y] -- ;
p[x][y1] -- ;
p[x1][y1] ++ ;
};
};
for(int i = 1; i <= n; i ++ )
for(int j = 1; j <= m; j ++ )
p[i][j] = (p[i][j] + p[i-1][j] + p[i][j-1] - p[i-1][j-1]);
int ans = 0;
for(int i = 1; i <= n; i ++ )
for(int j = 1; j <= m; j ++ )
ans += (s[i-1][j-1] == 'M' && p[i][j] >= k);
cout << ans << '\n';
};
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int tt = 1;
//cin >> tt;
while( tt -- ) {
solve();
};
};
