#include <cstdio>

using namespace std;

int a[20][20];

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

	int n, m, s = 0;
	scanf ("%d %d", &n, &m);

	for (int i = 0; i < n; i++)
		for (int j = 0; j < m; j++) {
			scanf("%d",&a[i][j]);
			s=s+a[i][j];
		}

	for (int i = 0; i < (1<<n); i++) {
		int p = 0;
		for (int k = 0; k < m; k++) {
			int s1 = 0, s2 = 0;
			for (int j = 0; j < n; j++){
			
				if ((1<<j) & i) {
					s1 = s1 - a[j][k];
					s2 = s2 + a[j][k];
				}
				else {
					s1 = s1 + a[j][k];
					s2 = s2 - a[j][k];
				}
			}
				if (s1<=s2){s1=s2;}

				p = p + s1;
			
		}
		if (s<=p){s=p;}
	
		
	}

	printf ("%d",s);

	return 0;

}