#include<stdio.h>   
FILE *f,*g;   
int main()   {
	long x[17][17],a[20],i,j,k,z,ss,s,max,m,n; 
	f=fopen("flip.in","r");
	g=fopen("flip.out","w");
	fscanf(f,"%ld%ld",&n,&m);   
 for(i=1;i<=n;i++)
	 for(j=1;j<=m;j++)
		 fscanf(f,"%ld",&x[i][j]);      
 a[1]=-1;
	k=1;   
 while(k)   {
	 z=0;
	 if(a[k]<1) {
		 a[k]++;
		 z=1;
	 }   
	if(z)
	  if(k==n)   {
		  ss=0;
			for(j=1;j<=m;j++)   {
				s=0;
				for(i=1;i<=n;i++)
					if(a[i])
						s+=x[i][j];
					else s-=x[i][j];
					if(s>0)
						ss+=s;
					else 
						ss-=s;
			}   
      if(ss>max)
		  max=ss;   
     }   
      else {
		  k++;
		  a[k]=-1;
	  }   
		else k--;  
 }
 fprintf(g,"%ld",max);
 return 0;   
}