#include <stdio.h>
FILE *f;
long x[17][17],a[20],i,j,k,z,ss,s,max,m,n;
int main()
{f=fopen("flip.in","r");fscanf(f,"%ld%ld",&n,&m);
 for(i=1;i<=n;i++)for(j=1;j<=m;j++)fscanf(f,"%ld",&x[i][j]);
 fclose(f);
 a[1]=-1;k=1;
 while(k)
 {z=0;if(a[k]<1){a[k]++;z=1;}
  if(z)if(k==n)
	 {ss=0;for(j=1;j<=m;j++)
	  {s=0;for(i=1;i<=n;i++)if(a[i])s+=x[i][j];else s-=x[i][j];if(s>0)ss+=s;else ss-=s;}
	  if(ss>max)max=ss;
	 }
	  else {k++;a[k]=-1;}

       else k--;
 }
 f=fopen("flip.out","w");fprintf(f,"%ld",max);fclose(f);
 return 0;
}