#include<stdio.h>

int sol[1001],n,m;

int a[17][17],max;

void read()
{
 scanf("%d %d",&n,&m);
 for(int i=1;i<=n;i++)
   for(int j=1;j<=m;j++)
     {scanf("%d",&a[i][j]);
      max=max+a[i][j];
      }
}

void calculeaza()
{
  int s=0,k,j,x;
  for (j=1; j<=m; j++)
    {x=0;
     for (k=1; k<=n; k++)
	 x=x+sol[k]*a[k][j];
     if (x<0)
		s=s-x;
	  else
		s=s+x;
      }
  if (s>max)
     max=s;

}

void print()
{
 printf("%d",max);
}
void back(int k)
{
	if(k==n+1)
	    calculeaza();
     else
       for(int val=-1;val<=1;val+=2)
       {
	    sol[k]=val;
	    back(k+1);
	}
}


int main()             
{
  freopen("flip.in","r",stdin);
  freopen("flip.out","w",stdout);
  read();
  back(1);
  print();
}