#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <immintrin.h>
#ifndef DEBUG
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
#endif
using namespace __gnu_pbds;
using namespace __gnu_cxx;
using namespace std;
//
using ld = long double;
using ll = long long;
using i128 = __int128;
using ull = unsigned long long;
using pll = std::pair<ll, ll>;
using cmpl = std::complex<ld>;
template<typename T>
using oset = tree<T, null_type, std::less<T>, rb_tree_tag, tree_order_statistics_node_update>;
constexpr ll MOD1 = 998244353;
constexpr ll MOD = 1000000007;
constexpr ll INV2 = 499122177;
constexpr ld PI = 3.141592653589793;
const ld eps = 1e-7;
const ll K = 500;
//const ll C = 200;
std::mt19937 rnd(std::chrono::steady_clock::now().time_since_epoch().count());
ld START_TIME = clock();
struct Fenwick{
std::vector<std::vector<ll>> f;
Fenwick(ll n, ll m){
f.resize(n + 1, std::vector<ll>(m + 1));
}
void add(ll i, ll j){
++i, ++j;
while (i < f.size()){
ll j1 = j;
while (j1 < f[i].size()){
++f[i][j1];
j1 += j1 & -j1;
}
i += i & -i;
}
}
ll get(ll x, ll y){
ll ans = 0;
while (x > 0){
ll j = y;
while (j > 0){
ans += f[x][j];
j -= j & -j;
}
x -= x & -x;
}
return ans;
}
ll get(ll x, ll y, ll x1, ll y1){
ll ddv = get(x1, y1) + get(x, y);
return ddv - get(x1, y) - get(x, y1);
}
};
void solve() {
ll n, m, d, k;
std::cin >> n >> m >> d >> k;
std::vector<std::string> a(n);
for (int i = 0; i < n; ++i) {
std::cin >> a[i];
}
Fenwick f(n, m);
for (int i = 0; i < n; ++i) {
for (int j = 0; j < m; ++j) {
if (a[i][j] == 'S'){
f.add(i, j);
}
}
}
ll ans = 0;
for (ll i = 0; i < n; ++i) {
for (ll j = 0; j < m; ++j) {
if (a[i][j] == 'M'){
ll cnt = f.get(std::max(0ll, i - d), std::max(0ll, j - d), std::min(i + d + 1, n), std::min(j + d + 1, m));
ans += cnt >= k;
}
}
}
std::cout << ans;
}
signed main() {
#ifdef DEBUG
std::freopen("/home/anton/CLionProjects/untitled/input.txt", "r", stdin);
#else
// std::freopen("tri.in", "r", stdin); std::freopen("tri.out", "w", stdout);
#endif
std::cin.tie(nullptr)->std::ios_base::sync_with_stdio(false);
int tt = 1;
// ll g; std::cin >> g;
// std::cin >> tt;
while (tt--) {
solve();
}
#ifdef DEBUG
std::cerr << '\n';
ld TIME = (clock() - START_TIME) / CLOCKS_PER_SEC;
std::cerr << "Time: " << TIME << '\n';
#endif
}
