#include<fstream>
using namespace std;
ifstream fi("flip.in");
ofstream fo("flip.out");
 
const int MAX_NM = 20; 
 
int i,j,n,m,a[MAX_NM][MAX_NM];
int sumc,s,smaxim;
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;
}