#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize("unroll-loops,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long ll;
typedef long double ld;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
ll r,c,d,k;
cin >> r >> c >> d >> k;
if (r == 1){
string temp;
cin >> temp;
vector <ll> s;
for (int z=0;z<temp.size();z++){
if (temp[z] == 'S') s.push_back(z);
}
ll ans = 0;
for (int z=0;z<temp.size();z++){
if (temp[z] == 'M'){
auto it = lower_bound(s.begin(),s.end(),z-d);
auto ita = upper_bound(s.begin(),s.end(),z+d);
if (ita - it >= k){
ans++;
}
}
}
cout << ans << endl;
return 0;
}
vector <string> arr(r);
vector <vector<ll>> count(r,vector<ll>(c,0));
for (int z=0;z<r;z++){
cin >> arr[z];
}
for (int z=0;z<r;z++){
for (int x=0;x<c;x++){
if (arr[z][x] == 'S'){
for (ll i = max(z-d,ll(0));i<=min(z+d,r-1);i++){
for (ll j = max(x-d,ll(0));j<=min(x+d,c-1);j++){
count[i][j]++;
}
}
}
}
}
ll ans = 0;
for (int z=0;z<r;z++){
for (int x=0;x<c;x++){
if (arr[z][x] == 'M'){
if (count[z][x] >= k) ans++;
}
}
}
cout << ans << endl;
}
