#include<stdio.h>
#include<values.h>
#include<math.h>
FILE*f=fopen("flip.in","r");
FILE*g=fopen("flip.out","w");
int m,n,d[2]={1,-1},st[17],st1[17];
long a[17][17],max=-MAXLONG,S;
void citire()
{int i,j;
 fscanf(f,"%d%d",&n,&m);
 for(i=1;i<=n;i++)
	for(j=1;j<=m;j++)
		fscanf(f,"%ld",&a[i][j]);
}
void bkt(int k)
{int i,j,x,p;
 long s,s1;
 for(i=0;i<2;i++)
	{st[k]=d[i];
	 if(k==n) {S=0;
		   for(j=1;j<=m;j++)
			{s=s1=0;
			 x=-1;
			 for(p=1;p<=n;p++)
				{s+=a[p][j]*st[p]*x;
				 s1+=a[p][j]*st[p]*x*x;}
			 if(s>s1) {st1[j]=x;
				   S+=s;}
			 else {st1[j]=x*x;
			       S+=s1;}
			}
		   if(S>max) max=S;
		  }
	 else bkt(k+1);
	}
}
int main()
{citire();
 bkt(1);
 fprintf(g,"%ld",max);
 fcloseall();
 return 0;
}