#include <stdio.h>

int main()
{
	int n,m,i,j,k,p;
	long a[16][16];
	int b;
	long s,s1;
	FILE *f=fopen("flip.in","r");
	FILE *g=fopen("flip.out","w");
	fscanf(f,"%d",&n);
	fscanf(f,"%d\n",&m);
	for (i=0; i<n; i++)
	{
		for (j=0; j<m; j++)
			fscanf(f,"%ld",&a[i][j]);
		fscanf(f,"\n");
	}
		for (i=0; i<n; i++)
			for (j=0; j<m; j++)
			{
				s=0;
				for (k=0; k<n; k++) s+=a[k][j];
				for (k=0; k<m; k++) s+=a[i][k];
				s-=a[i][j];
				s1=s;
				for (k=0; k<n; k++) s1-=2*a[k][j];
				if (s1>s) {
					for (k=0; k<n; k++) a[k][j]=-a[k][j];
					s=s1;
				}
				s1=s;
				for (k=0; k<m; k++) s1-=2*a[i][k];
				if (s1>s) {
					for (k=0; k<m; k++) a[i][k]=-a[i][k];
				}
			}	
	s=0;
	for (i=0; i<n; i++)
		for (j=0; j<m; j++) s+=a[i][j];
	fprintf(g,"%ld",s);
	fclose(f);
	fclose(g);
	return 0;
}