#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,a,b) for (int i=a; i<(b); ++i)
#define sz(x) (int)(x.size())
typedef vector<int> vi;
typedef pair<int,int> pii;
#define ll short;

struct Dinic {
	struct Edge {
		int to, rev;
		ll c, oc;
		ll flow() { return max(oc - c, 0LL); }
	};

	vi lvl, ptr, q;
	vector<vector<Edge>> adj;
	Dinic(int n) : lvl(n), ptr(n), q(n), adj(n) {}

	void addEdge(int a, int b, ll c, ll rcap = 0) {
		adj[a].push_back({b, sz(adj[b]), c, c});
		adj[b].push_back({a, sz(adj[a]) - 1, rcap, rcap});
	}

	ll dfs(int v, int t, ll f) {
		if (v == t || !f) return f;
		for (int& i = ptr[v]; i < sz(adj[v]); i++) {
			Edge& e = adj[v][i];
			if (lvl[e.to] == lvl[v] + 1)
				if (ll p = dfs(e.to, t, min(f, e.c))) {
					e.c -= p, adj[e.to][e.rev].c += p;
					return p;
				}
		}
		return 0;
	}

	ll calc(int s, int t) {
		ll flow = 0; q[0] = s;
		rep(L,30,31) do {
			lvl = ptr = vi(sz(q));
			int qi = 0, qe = lvl[s] = 1;
			while (qi < qe && !lvl[t]) {
				int v = q[qi++];
				for (Edge e : adj[v])
					if (!lvl[e.to] && e.c >> (30 - L))
						q[qe++] = e.to, lvl[e.to] = lvl[v] + 1;
			}
			while (ll p = dfs(s, t, LLONG_MAX)) flow += p;
		} while (lvl[t]);
		return flow;
	}
	bool leftOfMinCut(int a) { return lvl[a] != 0; }
};

int n,m;
long long c,d,cnt;
string s[255];

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>n>>m>>c>>d;
    for (int i=0; i<n; ++i) cin>>s[i];
    for (int i=0; i<n; ++i) for (int j=0; j<m; ++j) if (s[i][j]=='.') ++cnt;

    long long ans=cnt*d;
    for (ll k=1; k<=250; ++k) {
        if (rand()%4==0) continue;
        Dinic dnc=Dinic(n+m+2);
        for (int i=0; i<n; ++i) for (int j=0; j<m; ++j) if (s[i][j]=='.') dnc.addEdge(i,j+n,1);
        for (int i=0; i<n; ++i) dnc.addEdge(n+m,i,k);
        for (int i=n; i<n+m; ++i) dnc.addEdge(i,n+m+1,k);
        ll res=dnc.calc(n+m,n+m+1);
        ans=min(ans, c*k+d*(cnt-res));
        if (res==cnt) break;
    }
    cout<<ans<<"\n";
}

answer.code:8:12: error: declaration does not declare anything [-fpermissive]
    8 | #define ll short;
      |            ^~~~~
answer.code:13:17: note: in expansion of macro ‘ll’
   13 |                 ll c, oc;
      |                 ^~
answer.code:13:20: error: ‘c’ does not name a type
   13 |                 ll c, oc;
      |                    ^
answer.code:8:12: error: declaration does not declare anything [-fpermissive]
    8 | #define ll short;
      |            ^~~~~
answer.code:14:17: note: in expansion of macro ‘ll’
   14 |                 ll flow() { return max(oc - c, 0LL); }
      |                 ^~
answer.code:14:20: error: ISO C++ forbids declaration of ‘flow’ with no type [-fpermissive]
   14 |                 ll flow() { return max(oc - c, 0LL); }
      |                    ^~~~
answer.code:8:17: error: expected ‘)’ before ‘;’ token
    8 | #define ll short;
      |                 ^
answer.code:21:36: note: in expansion of macro ‘ll’
   21 |         void addEdge(int a, int b, ll c, ll rcap = 0) {
      |                                    ^~
answer.code:21:21: note: to match this ‘(’
   21 |         void addEdge(int a, int b, ll c, ll rcap = 0) {
      |                     ^
answer.code:21:39: error: ‘c’ does not name a type
   21 |         void addEdge(int a, int b, ll c, ll rcap = 0) {
      |                                       ^
answer.code:21:45: error: ‘rcap’ does not name a type
   21 |         void addEdge(int a, int b, ll c, ll rcap = 0) {
      |                                             ^~~~
answer.code:8:12: error: declaration does not declare anything [-fpermissive]
    8 | #define ll short;
      |            ^~~~~
answer.code:26:9: note: in expansion of macro ‘ll’
   26 |         ll dfs(int v, int t, ll f) {
      |         ^~
answer.code:8:17: error: expected ‘)’ before ‘;’ token
    8 | #define ll short;
      |                 ^
answer.code:26:30: note: in expansion of macro ‘ll’
   26 |         ll dfs(int v, int t, ll f) {
      |                              ^~
answer.code:26:15: note: to match this ‘(’
   26 |         ll dfs(int v, int t, ll f) {
      |               ^
answer.code:26:12: error: ISO C++ forbids declaration of ‘dfs’ with no type [-fpermissive]
   26 |         ll dfs(int v, int t, ll f) {
      |            ^~~
answer.code:26:33: error: ‘f’ does not name a type
   26 |         ll dfs(int v, int t, ll f) {
      |                                 ^
answer.code:8:12: error: declaration does not declare anything [-fpermissive]
    8 | #define ll short;
      |            ^~~~~
answer.code:39:9: note: in expansion of macro ‘ll’
   39 |         ll calc(int s, int t) {
      |         ^~
answer.code:39:12: error: ISO C++ forbids declaration of ‘calc’ with no type [-fpermissive]
   39 |         ll calc(int s, int t) {
      |            ^~~~
answer.code: In member function ‘int Dinic::Edge::flow()’:
answer.code:14:40: error: ‘oc’ was not declared in this scope
   14 |                 ll flow() { return max(oc - c, 0LL); }
      |                                        ^~
answer.code:14:45: error: ‘c’ was not declared in this scope
   14 |                 ll flow() { return max(oc - c, 0LL); }
      |                                             ^
answer.code: In member function ‘int Dinic::calc(int, int)’:
answer.code:8:12: error: declaration does not declare anything [-fpermissive]
    8 | #define ll short;
      |            ^~~~~
answer.code:40:17: note: in expansion of macro ‘ll’
   40 |                 ll flow = 0; q[0] = s;
      |                 ^~
answer.code:40:20: error: ‘flow’ was not declared in this scope
   40 |                 ll flow = 0; q[0] = s;
      |                    ^~~~
answer.code:47:61: error: ‘struct Dinic::Edge’ has no member named ‘c’
   47 |                                         if (!lvl[e.to] && e.c >> (30 - L))
      |                                                             ^
answer.code:8:17: error: expected unqualified-id before ‘;’ token
    8 | #define ll short;
      |                 ^
answer.code:50:32: note: in expansion of macro ‘ll’
   50 |                         while (ll p = dfs(s, t, LLONG_MAX)) flow += p;
      |                                ^~
answer.code:8:17: error: expected ‘)’ before ‘;’ token
    8 | #define ll short;
      |                 ^
answer.code:50:32: note: in expansion of macro ‘ll’
   50 |                         while (ll p = dfs(s, t, LLONG_MAX)) flow += p;
      |                                ^~
answer.code:50:31: note: to match this ‘(’
   50 |                         while (ll p = dfs(s, t, LLONG_MAX)) flow += p;
      |                               ^
answer.code:50:35: error: ‘p’ was not declared in this scope
   50 |                         while (ll p = dfs(s, t, LLONG_MAX)) flow += p;
      |                                   ^
answer.code:50:49: warning: overflow in conversion from ‘long long int’ to ‘short int’ changes value from ‘9223372036854775807’ to ‘-1’ [-...