#include<stdio.h>
 int n,m,a[17][17],b[17],st[3],max=-16000000;


 void prelucrare()
 {
   int s=0,s1=0,p;
  for(p=1;p<=m;p++)
  {  s1=0;
     for(int j=1;j<=n;j++)
       s1+=b[j]*a[j][p];
     if(s1>=0) s+=s1;
     else s+=-1*s1;

  }
  if(s>max) max=s;

 }

  void  bkt(int k)
 {
    if(k>n)   prelucrare();
    else
      for(int i=1;i<=2;i++)
       {
	 b[k]=st[i];
	 bkt(k+1);
       }


 }
  int main()
 {
   FILE *in;
   FILE *out;
   in=fopen("flip.in","r");
   out=fopen("flip.out","w");
   fscanf(in,"%d%d\n",&n,&m);
   st[1]=1;
   st[2]=-1;
   for(int i=1;i<=n;i++)
    for(int j=1;j<=m;j++)
      fscanf(in,"%d",&a[i][j]);
   bkt(1);
   fprintf(out,"%d",max);
   return 0;
 }