#include <bits/stdc++.h>
using namespace std;
int r, c, d, k, ans;
int main()
{
cin.tie(NULL)->sync_with_stdio(false);
cin>>r>>c>>d>>k;
vector<vector<int>> sw1(r+2, vector<int> (c+2)), sw2(r+2, vector<int> (c+2));
vector<vector<char>> mp(r+2, vector<char> (c+2));
for (int i=1; i<=r; i++)
{
for (int j=1; j<=c; j++)
{
cin>>mp[i][j];
if (mp[i][j]=='S')
{
sw1[max(0, i-d)][max(0, j-d)]++;
sw1[min(r+1, i+d+1)][max(0, j-d)]--;
sw1[max(0, i-d)][min(c+1, j+d+1)]--;
sw1[min(r+1, i+d+1)][min(c+1, j+d+1)]++;
}
}
}
for (int i=1; i<=r; i++) for (int j=0; j<=c; j++) sw1[i][j]+=sw1[i-1][j];
for (int i=0; i<=r+1; i++) for (int j=0; j<=c+1; j++) sw2[i][j]=sw1[i][j];
for (int i=1; i<=r; i++)
{
for (int j=1; j<=c; j++) sw2[i][j]+=sw2[i][j-1]; //cout<<sw2[i][j]<<' ';
// cout<<'\n';
}
for (int i=1; i<=r; i++) for (int j=1; j<=c; j++) if (mp[i][j]=='M'&&sw2[i][j]>=k) ans++;
cout<<ans;
}
