#include<fstream.h>
int main()
{
long a[18][18],b[18],s,ss,i,j,n,m;
ifstream f("flip.in");
ofstream g("flip.out");
f>>n>>m;
long max=0;
for (i=1;i<=n;i++)
	for (j=1;j<=m;j++)
		{
		f>>a[i][j];
		max+=a[i][j];
		}
while (b[0]==0)
	{
	i=n;
	while (b[i]==1)
		{
		b[i]=0;
		i--;
		}
	b[i]=1;
	s=0;
	for (j=1;j<=m;j++)
		{
		ss=0;
		for (i=1;i<=n;i++)
			if (b[i]==1) ss-=a[i][j];
			else ss+=a[i][j];
		if (ss<0) ss=-ss;
		s+=ss;
		}
	if (max<s) max=s;
	}
g<<max<<'\n';
f.close();
g.close();
return 0;
}