#include <fstream.h>
ifstream f("flip.in");
ofstream g("flip.out");
int a[17][17],x[17],m,n,k,Max;
void cit()
    {f>>n>>m;
    for (int i=1; i<=n; ++i)
		for (int j=1; j<=m; ++j)
			{f>>a[i][j];
			Max+=a[i][j];
			}
	}
void prel_sol ()
	{int suma_col = 0, suma_total = 0;
	for (int i=1; i<=m; ++i)
	{suma_col = 0;
	for (int j=1; j<=n; ++j)
		{if (x[j] == 1)suma_col += a[j][i];
		else suma_col+=  a[j][i] * (-1);
		}
	if(suma_col>0)suma_total += suma_col; else suma_total -=suma_col;
    }
    if (Max < suma_total)Max = suma_total;
}
  
void back (int k)
    {int t;
    for (t=1; t<=2; ++t)
    {x[k] = t;
     if (k==n)prel_sol();  else back (k + 1);
    }
}
  
 
int main ()
{cit();
back(1);
g<<Max<<'\n';
g.close();
f.close();
return 0;
}