#include<cstdio>
#include<cmath>

int smax=0;
int n,m;
int x[20][20], st[20];

void files()
{
	freopen("flip.in","r",stdin);
	freopen("flip.out","w",stdout);
}

void read()
{
	int i,j;
	files();
	scanf("%d%d",&n,&m);
	for (i=1;i<=n;++i)
		for (j=1;j<=m;++j)
			scanf("%d",&x[i][j]);
}


void solve()
{
	int sum1=0,sum2;
	int i,j;
		for (i=1;i<=n;++i)
		{
			sum2=0;
			for (j=1;j<=m;++j)
				sum2+=x[i][j]*st[j];
			if (sum2<-sum2) sum2*=-1;
			sum1+=sum2;
		}
	if (smax<sum1) smax=sum1;
}

void back(int k)
{
	if (k==m+1)
	{
		solve();
		return;
	}
	
	st[k]=1;
	back(k+1);
	st[k]=-1;
	back(k+1);
	
}

int main()
{
	read();
	back(1);
	printf("%d\n",smax);
	
	return 0;
}