//#pragma GCC target("avx2")
//#pragma GCC optimization("O3")
//#pragma GCC optimization("unroll-loops")
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ff first
#define ss second
#define pb push_back
#define SZ(x) ((int)(x).size())
#define all(x) x.begin(), x.end()
#define debug(x) cout << #x << ": " << x << " "
#define nl cout << "\n"
#define rep(i, a, b) for(int i = (a); i < (b); i++)
#define per(i, a, b) for(int i = (a); i >= (b); i--)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void solve(){
int R, C, D, K;
cin >> R >> C >> D >> K;
int a[R + 1][C + 1]; memset(a, 0, sizeof(a));
queue<pii> q;
rep(i, 0, R){
string s; cin >> s;
rep(j, 0, C){
if(s[j] == 'M'){
q.push({i, j});
} else if(s[j] == 'S'){
int mnx = max(0, i - D), mxx = min(R, i + D + 1);
int mny = max(0, j - D), mxy = min(C, j + D + 1);
a[mnx][mny]++;
a[mnx][mxy]--;
a[mxx][mny]--;
a[mxx][mxy]++;
}
}
}
rep(i, 0, R){
rep(j, 0, C){
a[i][j + 1] += a[i][j];
}
}
rep(i, 0, R){
rep(j, 0, C){
a[i + 1][j] += a[i][j];
}
}
int ans = 0;
while(!q.empty()){
auto [x, y] = q.front();
q.pop();
if(a[x][y] >= K)
ans++;
}
cout << ans;
}
int main(){
ios_base::sync_with_stdio(false), cin.tie(nullptr);
solve();
return 0;
}
