// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #include <x86intrin.h>
#include <bits/stdc++.h>
#include <chrono>
#include <random>
// @author: Vlapos
namespace operators
{
template <typename T1, typename T2>
std::istream &operator>>(std::istream &in, std::pair<T1, T2> &x)
{
in >> x.first >> x.second;
return in;
}
template <typename T1, typename T2>
std::ostream &operator<<(std::ostream &out, std::pair<T1, T2> x)
{
out << x.first << " " << x.second;
return out;
}
template <typename T1>
std::istream &operator>>(std::istream &in, std::vector<T1> &x)
{
for (auto &i : x)
in >> i;
return in;
}
template <typename T1>
std::ostream &operator<<(std::ostream &out, std::vector<T1> &x)
{
for (auto &i : x)
out << i << " ";
return out;
}
template <typename T1>
std::ostream &operator<<(std::ostream &out, std::set<T1> &x)
{
for (auto &i : x)
out << i << " ";
return out;
}
}
// name spaces
using namespace std;
using namespace operators;
// end of name spaces
// defines
#define ll long long
#define ull unsigned long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define f first
#define s second
#define uint unsigned int
#define all(vc) vc.begin(), vc.end()
// end of defines
// usefull stuff
void boost()
{
ios_base ::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
}
inline int getbit(int &x, int &bt) { return (x >> bt) & 1; }
const int dx4[4] = {-1, 0, 0, 1};
const int dy4[4] = {0, -1, 1, 0};
const int dx8[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
const int dy8[8] = {-1, -0, 1, -1, 1, -1, 0, 1};
const ll INF = 2e18;
const int BIG = (1e9) * 2 + 100;
const int MAXN = (1e5) + 5;
const int MOD7 = (1e9) + 7;
const int MOD9 = (1e9) + 9;
const uint MODFFT = 998244353;
// #define int ll`
struct segTreeSum
{
vector<ll> tree;
int sz;
void init(int n)
{
sz = n;
tree.resize(2 * sz);
}
void build(vector<int> &a)
{
init(a.size());
for (int i = 0; i < a.size(); ++i)
tree[i + sz] = a[sz];
for (int i = sz - 1; i > 0; --i)
tree[i] = tree[i << 1] + tree[(i << 1) + 1];
}
void add(int l, int r, int val) // [l, r)
{
l += sz;
r += sz;
while (l < r)
{
if (l & 1)
tree[l++] += val;
if (r & 1)
tree[--r] += val;
l >>= 1;
r >>= 1;
}
}
int get(int pos)
{
pos += sz;
int res = 0;
while (pos)
{
res += tree[pos];
pos >>= 1;
}
return res;
}
};
struct test
{
void solve(int testcase)
{
boost();
int n, m, d, k;
cin >> n >> m >> d >> k;
vector<vector<pair<pii, int>>> rls(n + 1);
vector<vector<int>> qrs(n);
for (int i = 0; i < n; ++i)
{
for (int j = 0; j < m; ++j)
{
char x;
cin >> x;
if (x == 'M')
qrs[i].pb(j);
else if (x == 'S')
{
rls[max(i - d, 0)].pb({{max(j - d, 0), min(j + d + 1, m)}, 1});
rls[min(i + d + 1, n)].pb({{max(j - d, 0), min(j + d + 1, m)}, -1});
}
}
}
segTreeSum tree;
tree.init(m);
int cnt = 0;
for (int i = 0; i < n; ++i)
{
for (auto [seg, v] : rls[i])
tree.add(seg.f, seg.s, v);
for (auto pos : qrs[i])
if (tree.get(pos) >= k)
cnt++;
}
cout << cnt << "\n";
}
};
main()
{
boost();
int q = 1;
// cin >> q;
for (int i = 0; i < q; i++)
{
test t;
t.solve(i);
}
return 0;
}
//[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]//
// //
// Coded by Der_Vlἀpos //
// //
//[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]//
