#include<stdio.h>
int a[16][16],max,m,n;
void suma()
{
	int sum,i,k,l,j,s[16];
	for (i=0;i<16;i++) s[i]=0;
	for (i=0,j=(1<<n);i<j;i++)
	{
		for (k=0; k<n; k++)
			if ((i>>k)&2)
				for (l=0;l<m;l++)
					s[l]-=a[k][l];
			else 
				for (l=0; l<m; l++)
					s[l]+=a[k][l];
		for (sum=l=0; l<m; s[l++]=0)
			if (s[l]>0) sum+=s[l];
			else sum-=s[l];
		if (sum>max) max=sum;
	}
}
int main()
{
	int i,j;
	freopen ("flip.in","r",stdin);
    freopen ("flip.out","w",stdout);
	scanf("%i%i",&n,&m);
	for (i=0;i<n;i++)
		for (j=0;j<m;j++)
			scanf("%i",&a[i][j]);
	suma();
	printf("%i",max);
	return 0;
}