#include <stdio.h>

int main()
{
	freopen ("flip.in", "r", stdin);
	
	int n,m, i, j;
	scanf ("%d%d", &n, &m);
	
	long a[16][16];
	for (i=0; i<n; ++i)
		for (j=0; j<m; ++j)
			scanf ("%ld", &a[i][j]);
	fclose(stdin);
	
	long smax=-999999999;
	unsigned int flip;
	for (flip=0; flip < (1<<n); ++flip)
	{
		long sf=0;
		for (i=0; i<n; ++i)
		{
			long s=0;
			for (j=0; j<m; ++j)
				if (flip & (1<<j))
					s-=a[i][j];
				else
					s+=a[i][j];
			if (s>0) sf+=s;
			else sf-=s;
		}
		
		if (sf>smax) smax=sf;
	}
	
	freopen ("flip.out", "w", stdout);
	printf ("%ld", smax);
	fclose(stdout);
	
	return 0;
}