#include<fstream>
#define maxnm 20
using namespace std;
ifstream fi("flip.in");
ofstream fo("flip.out");

int i,j,n,m,a[maxnm][maxnm];
int sumc,s,smaxim=0;
int nr;

int main(){
    fi>>n>>m;
    for(i=1;i<=n;i++)
      for(j=1;j<=m;j++){ fi>>a[i][j]; smaxim+=a[i][j]; }
    
    nr=(1<<n)-1;
    for(;nr>=0;nr--)
       {
        s=0;
        
        for(j=1;j<=m;j++)
           {
            sumc=0;
            for(i=1;i<=n;i++) if(nr&(1<<(i-1))) sumc+=a[i][j];
                              else sumc-=a[i][j];
            
            if(sumc>=0) s+=sumc;
            else s-=sumc;
           }
        
        if(s>smaxim) smaxim=s;
       }
    
    fo<<smaxim;
    
    fi.close();
    fo.close();
    return 0;
}