#include<fstream>
using namespace std;
int main()
{
	int a[20][20],i,j,n,m;
	long long max=0,s=0;
	ifstream f("flip.in");
	ofstream g("flip.out");
	f>>n>>m;
	for(i=1;i<=n;i++)
	{
		s=0;
		for(j=1;j<=m;j++)
		{
			f>>a[i][j];
			s=s+a[i][j];
		}
		if(s<0)
		{
			s=s*-1;
			for(j=1;j<=m;j++)
				a[i][j]=a[i][j]*-1;
		}
		a[i][m+1]=s;
	}
	for(j=1;j<=m;j++)
	{
		s=0;
		for(i=1;i<=n;i++)
			s=s+a[i][j];
		if(s<0)
		{
			s=s*-1;
			for(i=1;i<=n;i++)
				a[i][j]=a[i][j]*-1;
		}
		a[n+1][j]=s;
		max=max+s;
	}
	g<<max;
}