#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define endl '\n'
#define f first
#define s second
#define pb(x) push_back(x)
const int MOD = 1e9+7;
const int inf =1e9;
const ll INF = 1e18;
const ll INV2 = 500000004;
class DSU {
vector<int> parent, size;
public:
DSU(int n) {
parent.resize(n+1);
size.resize(n+1);
for (int i=0; i<=n; i++) {
parent[i]=i;
size[i]=1;
}
}
int find (int node) {
if (node==parent[node]) return node;
return parent[node]=find(parent[node]);
}
void unite (int u, int v) {
int pv=find(v);
int pu=find(u);
if (pv==pu) return;
if (size[pu]<size[pv]) swap(pu, pv);
parent[pv]=pu;
size[pu]+=size[pv];
}
int getsize (int node) {
return size[find(node)];
}
};
ll getsqrt(ll x) {
ll val = sqrtl(x) + 2;
while (val * val > x) val--;
return val;
}
bool safe (int i, int j, int n, int m) {
if (i<0 || j<0 || i>=n || j>=m) return false;
return true;
}
ll gcd(ll a, ll b) {
while (b != 0) {
ll temp=b;
b=a%b;
a=temp;
}
return a;
}
ll lcm(ll a, ll b) {
return a / gcd(a, b)*b;
}
vector<int> dx={-1, 0, 1, 0};
vector<int> dy={0, 1, 0, -1};
// SOLUTION STARTS FROM HERE //
void solve() {
int r, c, d, k;
cin>>r>>c>>d>>k;
vector<vector<char>> a(r, vector<char>(c));
for (int i=0; i<r; i++) {
for (int j=0; j<c; j++) {
cin>>a[i][j];
}
}
vector<vector<int>> add(r+2, vector<int>(c+2, 0));
for (int i=0; i<r; i++) {
for (int j=0; j<c; j++) {
if (a[i][j]=='S') {
int r1 = max(0, i-d);
int r2 = min(r-1, i+d);
int c1 = max(0, j-d);
int c2 = min(c-1, j+d);
add[r1][c1] += 1;
add[r1][c2+1] -= 1;
add[r2+1][c1] -= 1;
add[r2+1][c2+1] += 1;
}
}
}
vector<vector<int>> water(r, vector<int>(c));
for (int i=0; i<r; i++) {
for (int j=0; j<c; j++) {
water[i][j] = add[i][j];
if (i > 0) water[i][j] += water[i-1][j];
if (j > 0) water[i][j] += water[i][j-1];
if (i > 0 && j > 0) water[i][j] -= water[i-1][j-1];
}
}
int ans=0;
for (int i=0; i<r; i++) {
for (int j=0; j<c; j++) {
if (a[i][j]=='M' && water[i][j]>=k) {
ans++;
}
}
}
cout<<ans<<endl;
}
bool multi=false;
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
//freopen("convention2.in", "r", stdin);
//freopen("convention2.out", "w", stdout);
int t=1;
if (multi) cin>>t;
while (t--) solve();
return 0;
}
