//#pragma GCC target ("avx2")
//#pragma GCC optimize ("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define pb push_back
const int N = 1e3+100, NN=26;
const int mod=1e9+7;
int p[N][N];
//int gcd(int a, int b) { if (b == 0) return a; else return gcd(b, a % b); }
//int lcm(int a, int b) { return a / gcd(a, b) * b; }
//int binpow(int a,int b){if(!b)return 1; if(b&1)return a*binpow(a,b-1)%mod; int x=binpow(a,b/2); return x*x%mod;}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int r, c, d, k;
cin >> r >> c >> d >> k;
char a[r+1][c+1];
for(int i=1;i<=r;i++){
for(int j=1;j<=c;j++) cin >> a[i][j];
}
for(int i=1;i<=r;i++){
for(int j=1;j<=c;j++){
if(a[i][j]=='S'){
for(int ii=max(i-d, 1ll);ii<=min(i+d, r);ii++){
for(int jj=max(j-d, 1ll);jj<=min(j+d, c);jj++){
p[ii][jj]++;
}
}
}
}
}
int ans=0;
for(int i=1;i<=r;i++){
for(int j=1;j<=c;j++){;
if(a[i][j]=='M' && p[i][j]>=k) ans++;
}
}
cout << ans;
}
