#include<fstream.h>

#define min -1000001
#define xx 17

ifstream fin("flip.in");
ofstream fout("flip.out");

int s[xx],e[xx][xx],suma,n,m;

void suma_mat();
void back(int k);

int main()
{
    int i,j;
    fin>>n>>m;
    for(i=1;i<=n;i++)
      for(j=1;j<=m;j++)
        fin>>e[i][j];
    
    suma=min;
    
    back(1);
    
    fout<<suma<<'\n';
    fout.close();
    return 0;
}

void back(int k)
{
     if(k==m+1)
        suma_mat();
     else
     {
         s[k]=0;
         back(k+1);
         s[k]=1;
         back(k+1);
     }
}

void suma_mat()
{
     int slin=0,sum=0,i,j;
     
     for(i=1;i<=n;i++)
     {
       slin=0;
       for(j=1;j<=m;j++)
         if(s[j])
           slin-=e[i][j];
         else
           slin+=e[i][j];
       
       if(slin>0)
         sum+=slin;
       else
         sum-=slin;
     }
     if(suma<sum)
       suma=sum;
}