#include <stdio.h>
long n,m,a[16][16],st[16],smax;
FILE *f,*g;
void back(int k){
	int i,j,s,t;
	if (k==m)
	{
		s=0;
		for (i=0;i<n;i++)
		{	for (t=j=0;j<m;j++)
				if (st[j])
					t+=-a[i][j];
				else
					t+=a[i][j];
		s+=t<-t ? -t : t;
	}
	if (smax<s) smax=s;
	return;
    }
    st[k]=0; back(k+1);
    st[k]=1; back(k+1);
}

int main(){
	long i,j;
	f=fopen("flip.in","r");
	fscanf(f,"%ld %ld",&n,&m);
	for (i=0;i<n;i++)
		for (j=0;j<m;j++)
			fscanf(f,"%ld",&a[i][j]);
	back(0);
	fclose(f);

	g=fopen("flip.out","w");
	fprintf(g,"%ld\n",smax);
	fclose(g);
	return 0;
}