#include<stdio.h>   
  
FILE *f;   
#define In "flip.in"   
#define Out "flip.out"   
  
int n,m,a[16][16];   
int s[16],sum;   
int i,j,opt,nopt,max=0;   
  
int main()   
 {   
 f=fopen(In,"r");   
 fscanf(f,"%d%d",&n,&m);   
 for(i=0;i<n;i++)   
  for(j=0;j<m;j++)   
   fscanf(f,"%d",&a[i][j]);   
 for(opt=0,nopt=(1<<n);opt<nopt;opt++)   
  {   
  for(i=0;i<n;i++)   
   if((opt>>i)&1)   
    for(j=0;j<m;j++) s[j]-=a[i][j];   
   else  
    for(j=0;j<m;j++) s[j]+=a[i][j];   
  for(sum=j=0;j<m;s[j++]=0)   
   if(s[j]>0) sum+=s[j];   
   else sum-=s[j];   
  if(sum>max) max=sum;   
  }   
 freopen(Out,"w",f);   
 fprintf(f,"%d\n",max);   
 fclose(f);   
 return 0;   
 }