#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
typedef long long ll;
using namespace std;
ll r, c, d, k, ans;
int dx[4] = {1,-1,0,0};
int dy[4] = {0,0,-1,1};
ll grid[10000][10000];
bool inside(ll x, ll y){
return (x >= 1 && y >= 1 && x <= r && y <= c);
}
void check(ll x, ll y){
ll x1, x2, y1, y2;
x1 = x-d; x2 = x+d; y1 = y-d; y2 = y+d;
// cout << x1 << " " << x2 << " " << y1 << " " << y2 << "\n";
for(int i = x1; i <= x2; i++){
for(int j = y1; j <= y2; j++){
if(!inside(i,j)) continue;
if(grid[i][j] != -1){
grid[i][j]++;
if(grid[i][j] == k){
ans++;
}
}
}
}
}
int main(){
cin >> r >> c >> d >> k;
vector<pair<ll,ll>>spr;
for(int i = 1; i <= r; i++){
for(int j = 1; j <= c; j++){
char f; cin >> f;
if(f == '.') grid[i][j] = -1;
else if(f == 'M') grid[i][j] = 0;
else{
spr.pb({i,j});
grid[i][j] = -1;
}
}
}
for(pair<ll,ll> x : spr){
check(x.fi, x.se);
}
cout << ans << "\n";
}
