#include <stdio.h>                  
  int n,m,a[20][20],st[20],sol;                  
    void verif()            
     {            
         int i,j,aux,tot;            
         for(tot=0,i=0;i<n;i++)            
           {            
        for(j=0,aux=0;j<m;j++)            
          aux+=st[j]*a[i][j];            
        tot+=((aux>0)?aux:-aux);            
          }            
       if(tot>sol) sol=tot;            
     }            
              
   void back(int i)            
     {            
        if(i<m)            
          {            
         st[i]=1;            
         back(i+1);            
        st[i]=-1;            
 back(i+1);            
 }            
 else verif();            
 }                   
int main ()            
{            
FILE *fi=fopen("flip.in","r"),            
*fo=fopen("flip.out","w");            
int i,j;            
fscanf(fi,"%d %d",&n,&m);            
sol=-1;            
for(i=0;i<n;i++)            
for(j=0;j<m;j++)            
fscanf(fi,"%d",&a[i][j]);            
back(0);            
fprintf(fo,"%d",sol);            
return(0);   
}