#include<iostream>
#include<fstream>
using namespace std;
int i,j,a[16][16],n,m,s=0,smax=0,v[16];
void gestsumas()
{for (i=1;i<=n;i++)
	for (j=1;j<=m;j++)
		s=s+a[i][j]*v[i];
 if (s<0)
	 s=-s;
 smax=smax+s;
}
void back (int k)
{if (k>n)
	gestsumas();
 else
	 {for (i=0;i<=1;i++)
		 if (i==0)
			 v[k]=1;
		 else
			 v[k]=-1;
		 back (k+1);
	 }
}
int main ()
{ifstream f("flip.in");
 ofstream g("flip.out");
 f>>n;
 f>>m;
 for (i=1;i<=n;i++)
	for (j=1;j<=m;j++)
		 f>>a[i][j];	 
 back(1);
 cout<<smax;
 g<<smax;
 f.close();
 g.close();
 return 0;
}