# include <fstream>
# include <algorithm>
using namespace std;
ifstream f("elimin.in");
ofstream g("elimin.out");
int i,j,n,m,N,M,maxx,suma,VV,s[600];
int ap[20],a[600][600];
void back (int k, int VV)
{
    if (k>m+1) return;
    if (VV==M)
    {
        int i,j;
        for (i=1; i<=n; ++i)
        {
            s[i]=0;
            for (j=1; j<=m; ++j)
            {
                if (ap[j]==0) s[i]+=a[i][j];
            }
        }
        sort (s+1,s+n+1); suma=0;
        for (i=N+1; i<=n; ++i)
            suma+=s[i];
        if (suma>maxx) maxx=suma;
    }
    else
    {
        ap[k]=1;
          back(k+1,VV+1);
        ap[k]=0;
          back(k+1,VV);
    }
}
int main ()
{
    f>>n>>m>>N>>M;
    if (n<m) { swap(n,m); swap(N,M); }

    for (i=1; i<=n; ++i)
        for (j=1; j<=m; ++j)
            f>>a[i][j];
    back (1,0);
    g<<maxx<<"\n";

    return 0;
}