#include <iostream>

 #include <vector>

 #include <cstdio>

 #include <cstring>

 #include <algorithm>

 #include <cmath>

 #include <map>

 #include <set>

 #include <string>

 #include <queue>

 using namespace std;

 #define pb(x) push_back(x)

 #define ll long long

 #define mk(x, y) make_pair(x, y)

 #define lson l, m, rt<<1

 #define mem(a) memset(a, 0, sizeof(a))

 #define rson m+1, r, rt<<1|1

 #define mem1(a) memset(a, -1, sizeof(a))

 #define mem2(a) memset(a, 0x3f, sizeof(a))

 #define rep(i, a, n) for(int i = a; i<n; i++)

 #define ull unsigned long long

 typedef pair<int, int> pll;

 const double PI = acos(-1.0);

 const double eps = 1e-;

 const int mod = 1e9+;

 const int inf = ;

 const int dir[][] = { {-, }, {, }, {, -}, {, } };

 const int maxn = ;

 const int maxNode = ;

 struct DLX {

     int L[maxNode], R[maxNode], U[maxNode], D[maxNode], row[maxNode], col[maxNode];

     int S[maxn], H[maxn], deep, ans[maxn], sz, n, m, k, n1, m1;

     int g[][];

     void remove(int c) {

         for(int i = D[c]; i!=c; i = D[i]) {

             L[R[i]] = L[i];

             R[L[i]] = R[i];

         }

     }

     void resume(int c) {

         for(int i = U[c]; i!=c; i = U[i]) {

             L[R[i]] = i;

             R[L[i]] = i;

         }

     }

     int h() {

         int cnt = ;

         int vis[];

         mem(vis);

         for(int i = R[]; i!=; i = R[i]) {

             if(!vis[i]) {

                 cnt++;

                 vis[i] = ;

                 for(int j = D[i]; j!=i; j = D[j]) {

                     for(int k = R[j]; k!=j; k = R[k]) {

                         vis[col[k]] = ;

                     }

                 }

             }

         }

         return cnt;

     }

     void dfs(int d) {

         if(d+h()>=deep)

             return ;

         if(R[] == ) {

             deep = min(deep, d);

             return ;

         }

         int c = R[];

         for(int i = R[]; i!=; i = R[i])

             if(S[c]>S[i])

                 c = i;

         for(int i = D[c]; i!=c; i = D[i]) {

             remove(i);

             for(int j = R[i]; j!=i; j = R[j])

                 remove(j);

             dfs(d+);

             for(int j = L[i]; j!=i; j = L[j])

                 resume(j);

             resume(i);

         }

         return ;

     }

     void add(int r, int c) {

         sz++;

         row[sz] = r;

         col[sz] = c;

         S[c]++;

         U[sz] = U[c];

         D[sz] = c;

         D[U[c]] = sz;

         U[c] = sz;

         if(~H[r]) {

             R[sz] = H[r];

             L[sz] = L[H[r]];

             L[R[sz]] = sz;

             R[L[sz]] = sz;

         } else {

             H[r] = L[sz] = R[sz] = sz;

         }

     }

     void init(){

         mem1(H);

         for(int i = ; i<=n; i++) {

             R[i] = i+;

             L[i] = i-;

             U[i] = i;

             D[i] = i;

         }

         deep = inf;

         mem(S);

         R[n] = ;

         L[] = n;

         sz = n;

     }

     void solve() {

         mem(g);

         int cnt = , x;

         for(int i = ; i<n; i++) {

             for(int j = ; j<m; j++) {

                 scanf("%d", &x);

                 if(x)

                     g[i][j] = ++cnt;

                 else

                     g[i][j] = ;

             }

         }

         scanf("%d%d", &n1, &m1);

         int r = , tmp = n;

         n = cnt;

         init();

         for(int i = ; i<tmp-n1+; i++) {

             for(int j = ; j<m-m1+; j++) {

                 r++;

                 for(int k1 = i; k1<min(i+n1, tmp); k1++) {

                     for(int k2 = j; k2<min(j+m1, m); k2++) {

                         if(g[k1][k2]) {

                             add(r, g[k1][k2]);

                         }

                     }

                 }

             }

         }

         dfs();

         printf("%d\n", deep);

     }

 }dlx;

 int main()

 {

     while(scanf("%d%d", &dlx.n, &dlx.m)!=EOF) {

         dlx.solve();

     }

     return ;

 }