#include <stdio.h>
#define INFINIT 300000000

int matr[17][17];
//int stiva[17];
int n,m;

inline int suma(int nr){
 int i,j;
 int suma=0,suma_col;
 for(i=0;i<m;i++){
   suma_col=0;
   for(j=0;j<n;j++){//daca dau de vreo coloana cu suma negativa, o inm cu -1
      if(/*stiva[i]*/(nr&(1<<i))==1){//impar
        suma_col-=matr[i][j];
      }else suma_col+=matr[i][j];
   }
   if(suma_col<0)suma-=suma_col; 
     else suma+=suma_col;
 }
  return suma;

}

int rezolva(){
   int i=0;
   int sum=-INFINIT;
   int aux;
   for(i=0;i<n;i++){
      //pt configuratia i
      aux=suma(i);
      if(sum<aux)sum=aux;
   }
   return sum;
}

/*int bktr(){
   int sum=-INFINIT;
   int k=m;
   int loc=k;
   int aux;
   //stiva e initializata cu 0 (nu schimb nimic)
   while(loc>=0){
     if(loc==k){
        aux=suma();
        if(sum<aux)sum=aux;
        loc--;
     }
     stiva[loc]++;
     if(stiva[loc]>1){//pas inapoi
        stiva[loc]=-1;
        loc--;
     }else loc++;
   }
   return sum;
}*/

int main(){
  int i,j;
  freopen("flip.in","r",stdin);
  freopen("flip.out","w",stdout);
  scanf("%d%d",&m,&n);
  for(i=0;i<m;i++)
    for(j=0;j<n;j++)
      scanf("%d",&matr[i][j]);

  printf("%d\n",rezolva());
  return 0;
}