#include <bits/stdc++.h>
using namespace std;
using db = long double;
using ll = long long;
using pl = pair<ll, ll>;
using pi = pair<int, int>;
#define vt vector
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(), x.end()
#define size(x) ((int) (x).size())
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define ROF(i, a, b) for (int i = (b) - 1; i >= (a); i--)
#define F0R(i, b) FOR (i, 0, b)
#define endl '\n'
const ll INF = 1e18;
const int inf = 1e9;
template<typename Tuple, size_t... Is>
void print_tuple(const Tuple& t, index_sequence<Is...>) {
((cerr << (Is == 0 ? "{" : ", ") << get<Is>(t)), ...);
cerr << "}";
}
template<typename... Args>
ostream& operator<<(ostream& os, const tuple<Args...>& t) {
print_tuple(t, index_sequence_for<Args...>{});
return os;
}
ostream& operator<<(ostream& os, string& s) {
for (char c : s) os << c;
return os;
}
template<template<typename> class Container, typename T>
ostream& operator<<(ostream& os, Container<T> o) {
os << "{";
int g = size(o);
for (auto i : o) os << i << ((--g) == 0 ? "" : ", ");
os << "}";
return os;
}
template<typename T, typename V>
ostream& operator<<(ostream& os, const pair<T, V> p) {
os << "{" << p.f << ", " << p.s << "}";
return os;
}
template <typename T, typename... V>
void printer(const char *names, T &&head, V &&...tail) {
int i = 0;
while (names[i] != '\0' && names[i] != ',') i++;
constexpr bool is_str = is_same_v<decay_t<T>, const char*>;
if constexpr (is_str) cerr << head; // ignore directly passed strings
else cerr.write(names, i) << " = " << head;
if constexpr (sizeof...(tail)) cerr << (is_str ? "" : ","), printer(names + i + 1, tail...);
else cerr << endl;
}
#ifdef LOCAL
#define dbg(...) std::cerr << __LINE__ << ": ", printer(#__VA_ARGS__, __VA_ARGS__)
#else
#define dbg(x...)
#define cerr if (0) std::cerr
#endif
int rs, cs, d, k;
main() {
cin.tie(0)->sync_with_stdio(0);
cin >> rs >> cs >> d >> k;
vt<vt<int>> grid(rs, vt<int>(cs));
vt<pi> cows;
F0R (r, rs) {
F0R (c, cs) {
char ch; cin >> ch;
if (ch == '.') continue;
if (ch == 'M') {
cows.pb({r, c});
continue;
}
int r1 = max(0, r - d);
int c1 = max(0, c - d);
int r2 = min(rs - 1, r + d) + 1;
int c2 = min(cs - 1, c + d) + 1;
grid[r1][c1]++;
if (r2 < rs) grid[r2][c1]--;
if (c2 < cs) grid[r1][c2]--;
if (r2 < rs && c2 < cs) grid[r2][c2]++;
}
}
F0R (r, rs) F0R (c, cs - 1) grid[r][c + 1] += grid[r][c];
F0R (r, rs - 1) F0R (c, cs) grid[r + 1][c] += grid[r][c];
int ans = 0;
for (auto [x, y] : cows) ans += grid[x][y] >= k;
cout << ans << endl;
}
