// Codeforces Beta Round #45
// Problem B - Land Lot
// by daftc0d3r

#include <cstdio>
#include <algorithm>
using namespace std;
#define loop(i,a,b) for(int i=a; i<b; ++i)

int a[50][50], n, m, x, y;
int main ()
{
        scanf("%d%d", &n, &m);
        loop(i,0,n) {
                loop(j,0,m) {
                        scanf( "%d", &a[i][j] );
                }
        }
        scanf("%d%d", &x, &y);
        int res = n*m;
        
        loop(rev,0,2) {
                loop(i,0,n-x+1) {
                        loop(j,0,m-y+1) {
                                int cres = 0;
                                loop(ii,i,i+x) loop(jj,j,j+y)
                                        cres += a[ii][jj];
                                res = min ( cres, res );
                        }
                }
                swap(x,y);
        }
        printf("%d", res);
        return 0;
}