#include<stdio.h>
int a[100][100],i,j,k;

int main() {
 FILE* f=fopen("flip.in","r");
 FILE* g=fopen("flip.out","w");
 for (i=0;i<n;i++)
    for (j=0;j<m;j++) {  
       fscanf(f,"%d",&a[i][j]); 
     }

 for (k=0;k<=doi;k++){
	 for (b=0;b<m;b++) {
       if ((k>>b)&1) {  
     for (i=0;i<n;i++)  
       X[i][b] = -a[i][b];  
       } else {  
     for (i=0;i<n;i++)  
       X[i][b] = a[i][b];  
       }  
     }  
   
     sumC = 0;  
     for (i=0;i<n;i++) {  
       si = 0;  
       for (j=0;j<m;j++)  
     si+=X[i][j]; 
       if (si>0) sumC += si;  
       else sumC -= si;  
     }  
   
     if (sumC>sumMax)  
       sumMax = sumC;  
   
   }  
   
  
   fprintf(g,"%d",sumMax);






 fclose(f);
 fclose(g);
 return 0;
}