#include<stdio.h>
#define MAX 25
 
int modul (int m);

int main(){

int x,n,m,a[MAX][MAX],s,sol[MAX],max,k,sum;
int sign,col,i,j;
	max=-MAX;
	FILE *in=fopen("flip.in","r");
	FILE *out=fopen("flip.out","w");
	fscanf(in,"%d %d",&n,&m);
	int tmp=1;
	for(i=1;i<=n;i++){
		tmp*=2;
		for(j=1;j<=m;j++)
		{
			fscanf(in,"%d",&a[i][j]);					
		}}
	for(i=0;i<tmp;i++){
		k=i;
		sum=0;
		for(j=1;j<=m;j++) 
			sol[j]=0;
			for(j=1;j<=n;j++){
				if (k%2==1)	
					sign=-1;
				else 
					sign=1;
			k=k>>1;
			for(col=1;col<=m;col++)
			{
				sol[col]+=sign*(a[j][col]);
			}
		}
		for(j=1;j<=m;j++) sum+=modul(sol[j]);
		if (sum>max) 
			max=sum;
		}
	fclose(in);
	fprintf(out,"%d",max);
	fclose(out);
return 0;
}


int modul (int m) {
	if (m>0) return m; 
	else return -m;
}