#include<cstdio>
#include<cstring>
using namespace std;
int n,i,j,k,m;
int a[20][20],b[20][20];
long long linie[20],coloana[20],max,rez,smax,s,min;

long long suma()
{
	long long  tt;
	tt=0;
	for (j=1;j<=m;j++) tt+=coloana[j];
	return tt;
}
int main()
{
	freopen("flip.in","r",stdin);
	freopen("flip.out","w",stdout);
	scanf("%d %d",&n,&m);
	for (i=1;i<=n;i++) 
		for (j=1;j<=m;j++) scanf("%d",&a[i][j]),linie[i]+=a[i][j],coloana[j]+=a[i][j];
	for (i=1;i<=n;i++)
	{
		s=4000000000;
		for (j=1;j<=m;j++) if (coloana[j]<s) s=coloana[j],min=j;
		coloana[min]*=-1;
		for (k=1;k<=n;k++) a[k][min]*=-1,linie[k]+=(a[k][min]*2);
		if (suma()>smax) smax=suma();
		s=4000000000;
		for (j=1;j<=n;j++) if (linie[j]<s) s=linie[j],min=j;
		linie[min]*=-1;
		for (k=1;k<=n;k++) a[min][k]*=-1,coloana[k]+=(a[min][k]*2);
		if (suma()>smax) smax=suma();
	}
	printf("%lld",smax);
	return 0;
}