#include <cstdio>
#include <cmath>
#define NMax 21

int maxx,n,m,a[NMax][NMax],flip[NMax];

void print() {
	int sum,rez=0;
	for(int i=1;i<=n;i++) {
		sum=0;
		for(int j=1;j<=m;j++)
			sum+=a[i][j]*flip[j];
		rez+=fabs(sum);
	}
	if(rez>maxx)
		maxx=rez;
}

void bkt(int poz) {
	if(poz==m+1)
		print();
	else {
		flip[poz]=1;
		bkt(poz+1);
		flip[poz]=-1;
		bkt(poz+1);
	}

}

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

	scanf("%d %d",&n,&m);
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++)
			scanf("%d",&a[i][j]),maxx+=a[i][j];;

	bkt(1);
	
	printf("%d\n",maxx);

	return 0;
}