#include <fstream>
#include <iostream>
#include <math.h>
#include <bitset>
using namespace std;

ifstream fin ("elimin.in");
ofstream fout ("elimin.out");
int m, n, r, c, aux[87][87], x[87][87];

int suma(unsigned long long sub_lin, unsigned long long sub_col)
{
    int i, j, k, s = 0;
    
    for (i = 1; i<= n; i++)
        for (j = 1; j<= m; j++)
            aux[i][j] = x[i][j];
    
    for (j = 0; j<n; j++)
        if (((sub_lin >> j) & 1) != 0)
            for (i=1; i<=n; i++)
                aux[j+1][i] = 0;
    
    for (k = 0; k<m; k++)
        if (((sub_col >> k) & 1) != 0)
            for (i=1; i<=m; i++)
                aux[i][k+1] = 0;
    
    for (i = 1; i<= n; i++)
        for(j = 1; j<= m; j++)
            s += aux[i][j];
    
    return s;
}


int main()
{
 
    int i, j;
    unsigned long long submult_lin, submult_col, counter;
    int l, k, s_max=0, s;
    
    fin >> n >> m >> r >> c;
    for (i = 1; i<= n; i++)
        for(j = 1; j<= m; j++)
            fin >> x[i][j];
    
    submult_lin = (1<<n)-1;
    submult_col = (1<<m) -1;
    for (i = 1; i<=submult_lin; i++)
    {
        counter = 0;
        for (j = 0; j<n; j++)
            if (((i >> j) & 1) != 0)
                counter++;
        if (counter == r)
        {
            for (l = 1; l<=submult_col; l++)
            {
                counter = 0;
                for(k = 0; k<m; k++)
                    if (((l >> k) & 1) != 0)
                        counter++;
                if (counter==c)
                {
                    s = suma(i,l);
                    if (s > s_max)
                        s_max = s;
                }
            }
        }
    }
    fout << s_max;
    return 0;
}