#include<iostream>
#include<fstream>
#include<math.h>
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");
long long a[17][17],stotal1,stotal2,summinus,sumplus;
int main()
{
int n,m,i,j,k;
	f>>n>>m;
	for(i=1;i<=n;i++)
	{
		summinus=0;
		sumplus=0;
		for(j=1;j<=m;j++)
		{
			f>>a[i][j];
			if(a[i][j]<0)
				summinus=summinus+a[i][j];
			else
				sumplus=sumplus+a[i][j];
		}
		if((-1)*summinus>sumplus)
		{
			for(k=1;k<=m;k++)
			{
				a[i][k]=a[i][k]*(-1);
			}
			stotal1=stotal1+(-1)*summinus-sumplus;
		}
		else
			stotal1=stotal1+sumplus+summinus;
	}
	for(i=1;i<=m;i++)
	{
		summinus=0;
		sumplus=0;
		for(j=1;j<=n;j++)
		{
			if(a[j][i]<0)
				summinus=summinus+a[j][i];
			else
				sumplus=sumplus+a[j][i];
		}
		if((-1)*summinus>sumplus)
		{
			for(k=1;k<=n;k++)
			{
				a[k][i]=a[k][i]*(-1);
			}
			stotal2=stotal2+(-1)*summinus-sumplus;
		}
		else
			stotal2=stotal2+sumplus+summinus;
		
	}
	g<<max(stotal2,stotal1);
	return 0;
}