#include <fstream.h>   
#define El 16   
       
long A[El][El],B[El],aux1,aux2,max;      
unsigned int n,m,i,j,x;      
  
  
int main()
{        
    ifstream In("flip.in");      
        ofstream Out("flip.out");   
    In>>n>>m;      
    for(i=0;i<n;i++)        
           for(j=0;j<m;j++)  In>>A[i][j];   
    In.close();   
        
    while(x>=0)    
    {     
        if(B[x]==1)    
        {    
            B[x]=0;        
                        x--;        
                        continue;        
                }        
                else if(B[x]==-1)    
        {   
            B[x]=1;   
        }        
                        
                else B[x]=-1;   

		if(x==m)
	{
	    aux1=0;
			for(i=0;i<n;i++)
	    {
		aux2=0;
				for(j=0;j<m;j++)  aux2+=A[i][j]*B[j];
				if(aux2<0)  aux1-=aux2;
		else aux1+=aux2;
			}

			if(aux1>max) max=aux1;
			continue;
		 }
		 x++;
	}
    Out<<max<<'\n';

    Out.close();
    return 0;
}