#include<stdio.h>

long int a[17][17],st[17];
int n,m,suma;

void fsuma()
{
	int i,j,s=0;
	for(i=1;i<=n;i++)
		for(j=1;j<=m;j++)
			s+=a[i][j];

	if(s>suma)suma=s;
}

void back(int k)
{
	int i;
	for(i=-1;i<=1;i+=2)
	{
		st[k]=i;
		if(k==m)
        	fsuma();
		else
        	back(k+1);
    }
}


int main()
{

	int i,j;
	freopen("flip.in","r",stdin);
	freopen("flip.out","w",stdout);

	scanf("%d%d",&n,&m);
	for(i=1;i<=n;i++)
		for(j=1;j<=m;j++)
		scanf("%d",&a[i][j]);
    back(1);
	printf("%d",suma);
    return 0;
}