#include<stdio.h>
int a[10][10],n,m;
void citire(){
  FILE *f;
  f=fopen("flip.in","r");
  fscanf(f,"%d%d",&n,&m);
  for(int i=0;i<n;i++)
    for(int j=0;j<m;j++)
      fscanf(f,"%d",&a[i][j]);
}
void comutare(int i,int j){
  for(int k=0;k<m;k++)
    a[i][k]*=-1;
  for(int k=0;k<n;k++)
    a[k][j]*=-1;
  a[i][j]*=-1;
}
int suma(int i,int j){
  int s=0;
  for(i=0;i<n;i++)
    for(j=0;j<m;j++)
      s+=a[i][j];
  return s;
}
void rezolvare(){
  FILE *g;
  g=fopen("flip.out","w");
  int s,smax=0;
  for(int i=0;i<n;i++)
    for(int j=0;j<m;j++){
      comutare(i,j);
      s=suma(i,j);
      if(s>smax)
	smax=s;
      comutare(i,j);
    }
  fprintf(g,"%d",smax);
  fclose(g);
}
int main(){
  citire();
  rezolvare();
  return 0;
}