#include <fstream>
using namespace std;
ifstream fi("flip.in");
ofstream fo("flip.out");
long long  a[17][17],i,j,maxi,sum,ii,jj,m,n;
int main()
{fi>>n>>m;
for(i=1;i<=n;i++) for(j=1;j<=m;j++)fi>>a[i][j];

for(i=1;i<=n;i++) for(j=1;j<=m;j++)
{sum=0;
for(ii=1;ii<=n;ii++) for(jj=1;jj<=m;jj++)
  {if ((ii!= i and jj != j) or (ii== i and jj == j)) sum+=a[ii][jj];
   if ((ii== i and jj != j) or (ii!= i and jj == j)) sum+=a[ii][jj]*(-1);
  }
maxi=max(maxi,sum);
}
fo<<maxi;
    return 0;
}